BR112015002311B1 - Electrical ablation device and method of treating tissue electrosurgically - Google Patents

Abstract

FLEXIBLE EXPANDABLE ELECTRODE AND PULSED ENERGY INTRALUMINAL APPLICATION METHOD. The present invention relates to a surgical instrument, such as an electrical ablation device, that includes an elongate element having disposed along it a first electrode extending along an axis. A first expandable portion extends along the axis and defines a first perimeter of the first electrode and has an associated first diameter with respect to the axis. The first expandable portion includes a first selectively expandable structure for transitioning the first expandable portion from a contracted state to an expanded state. The first structure is selectively contractile to transition the first expandable portion from the expanded state to the contracted state. When the first structure is expanded, the first diameter is expanded and the first expandable portion transitions from the contracted state to the expanded state. When the first structure is contracted, the first diameter is contracted and the first expandable portion transitions from the expanded state to the contracted state.

Description

BACKGROUND

[0001] Electrical ablation therapy has been used in medicine for the treatment of unwanted tissue, such as diseased tissue, cancer, benign and malignant tumors, masses, lesions, and other abnormal tissue growths. Devices, systems, and methods for conventional ablation therapies may include electrical ablation therapies, such as, for example, high temperature thermal therapies including focused ultrasonic ablation, radiofrequency (RF) ablation, and laser interstitial coagulation, chemical therapies in which chemical agents are injected into unwanted tissue to cause ablation, surgical excision, cryotherapy, radiation, photodynamic therapy, Moh micrographic surgery, topical 5-fluorouracil treatments, and laser ablation.

[0002] Disadvantages of conventional electrical ablation therapies include risk of permanent damage to healthy tissue that surrounds unwanted tissue due to exposure to thermal energy and/or lack of controlled energy generated by an electrical ablation device. Thus, when unwanted tissue occurs or originates in or near critical structures and surgical resection presents an increased risk of morbidity associated with damage to this critical structure, conventional electrical ablation therapies may be an unsatisfactory alternative. From time to time, the ability to apply controlled energy to excise cells within a target zone may be affected by one or more characteristics of the target zone and/or available application positions provided by ablative electrodes. Solutions to address the above problems are often invasive and conflict with optimal surgical outcomes. Consequently, minimally invasive electrical ablation therapy capable of precisely directing ablative electrodes to a target site and applying controlled energy to extirpate cells within a target zone while retaining the necessary infrastructure of surrounding tissue is desirable.

SUMMARY

[0003] In a general aspect, the various modalities are directed towards an electrical ablation device. One embodiment of the electrical ablation device includes an elongate element having disposed along it a first electrode extending along an axis. The first electrode has a proximal end configured to mate with an energy source and a surface configured to mate with a tissue treatment region and deliver ablative energy. A first expandable portion extends along the axis and defines a first perimeter of the first electrode and has an associated first diameter with respect to the axis. The first expandable portion includes a first frame comprising at least one first frame member. The first structure is selectively expandable to transition the first expandable portion from a contracted state to an expanded state. The first structure is selectively contractile to transition the first expandable portion from the expanded state to the contracted state. When the first structure is expanded, the first diameter is expanded and the first expandable portion transitions from the contracted state to the expanded state. When the first structure is contracted, the first diameter is contracted and the first expandable portion transitions from the expanded state to the contracted state.

[0004] In another general aspect, a method of treating tissue using the electrical ablation devices described herein includes applying the first electrode to a tissue treatment region that includes a biological lumen and expanding the first electrode. The first electrode is placed in contact with a wall of the proximal lumen in the tissue to be treated. The tissue is treated by applying one or more sequences of electrical pulses to the first electrode to induce cell death in the tissue by irreversible electroporation.

FIGURES

[0005] The various modalities of electrical ablation devices, systems, and methods thereof described herein can be better understood by considering the following description in conjunction with the accompanying drawings.

[0006] Figure 1 illustrates an electrical ablation system according to certain modalities described herein.

[0007] Figure 2 illustrates an embodiment of the cable and elongated element illustrated in Figure 1 with the expandable portion of the electrode installed and in an expanded state in accordance with certain embodiments described herein.

[0008] Figure 3 illustrates an electrode disposed along a distal portion of an elongated element in which the expandable portion is installed and in an expanded state in accordance with certain embodiments described herein.

[0009] Figure 4 illustrates two electrodes disposed along a distal portion of an elongated element in which the respective expandable portions are installed and in expanded states in accordance with certain embodiments described herein.

[00010] Figure 5 illustrates three electrodes disposed along a distal portion of an elongated element in which respective expandable portions are installed and in expanded states in accordance with certain embodiments described herein.

[00011] Figure 6 illustrates a flexible portion of an electrode disposed along a distal portion of an elongate element in accordance with certain embodiments described herein.

[00012] Figure 7 illustrates an installed expandable portion of an electrode in an expanded state in accordance with certain embodiments described herein.

[00013] Figure 8 illustrates a cutaway view of an expandable portion received within a channel defined within a sheath wherein the expandable portion is in a contracted state in accordance with certain embodiments described herein.

[00014] Figure 9 illustrates the expandable portion illustrated in Figure 8 installed from the distal end of the sheath and in an expanded state in accordance with certain embodiments described herein.

[00015] Figure 10 illustrates an expandable portion installed in an expanded state in accordance with certain embodiments described herein.

[00016] Figure 11 illustrates an installed expandable portion that transitions from a contracted state to an expanded state in accordance with certain embodiments described herein.

[00017] Figure 12 illustrates an expandable portion in an expanded state in accordance with certain embodiments described herein.

[00018] Figure 13 illustrates an expandable portion that transitions from a contracted state to an expanded state in accordance with certain embodiments described herein.

[00019] Figure 14 illustrates the expandable portion illustrated in Figure 13 in an expanded state in accordance with certain embodiments described herein.

[00020] Figure 15 illustrates an expandable portion that transitions from a contracted state to an expanded state in accordance with certain embodiments described herein.

[00021] Figure 16 illustrates the expandable portion illustrated in Figure 15 in an expanded state in accordance with certain embodiments described herein.

[00022] Figure 17 illustrates an expandable portion that transitions from a contracted state to an expanded state in accordance with certain embodiments described herein.

[00023] Figure 18 illustrates an expandable portion installed in a contracted state in accordance with certain embodiments described herein.

[00024] Figure 19 illustrates the expandable portion illustrated in Figure 18 in an expanded state in accordance with certain embodiments described herein.

[00025] Figure 20 illustrates a further embodiment of the expandable portion illustrated in Figure 18 in an expanded state in accordance with certain embodiments described herein.

[00026] Figure 21 illustrates an expandable portion partially installed and in a contracted state in accordance with certain embodiments described herein.

[00027] Figure 22 illustrates the expandable portion illustrated in Figure 21 in an expanded state in accordance with certain embodiments described herein.

[00028] Figure 23 illustrates a further embodiment of the expandable portion illustrated in Figure 21 and Figure 22 in an expanded state in accordance with certain embodiments described herein.

[00029] Figure 24 illustrates an expandable portion in an expanded state in accordance with certain embodiments described herein.

[00030] Figure 25 illustrates the expandable portion illustrated in Figure 24 in a contracted state in accordance with certain embodiments described herein.

[00031] Figure 26 illustrates an electrical ablation device comprising a handle and an elongate element in accordance with certain embodiments described herein.

[00032] Figure 27 illustrates an electrical ablation device comprising a handle and an elongate element in accordance with certain embodiments described herein.

[00033] Figures 28A-B include photographs of porcine liver tissues after receiving electrical ablation according to certain modalities described herein.

[00034] Figure 29 includes a photograph of porcine heart tissues after receiving electrical ablation according to certain modalities described herein.

[00035] Figure 30 is a graphic representation of a use of the electrical ablation system according to certain modalities described herein.

DESCRIPTION

[00036] The present description generally refers to the field of electrosurgery. In particular, the present description relates to, although not exclusively, electrosurgical devices. More particularly, the present description relates to, though not exclusively, electrical ablation systems, devices, and methods.

[00037] This description describes various elements, features, aspects, and advantages of various modalities of electrical ablation systems, devices, and methods thereof. It is to be understood that certain descriptions of the various modalities have been simplified to illustrate only those elements, features and aspects that are relevant to a clearer understanding of the revealed modalities, while eliminating, for purposes of brevity or clarity, other elements, features and aspects. Any references to "various embodiments," "certain embodiments," "some embodiments," or "one embodiment" generally means that a particular element, feature, and/or aspect described in the embodiment is included in at least one embodiment. The phrases "in various modes," "in certain modes," "in some modes," or "in one mode" may not refer to the same mode. Furthermore, the phrases "in such a modality" or "in certain such modalities," although they generally refer to and are elaborated upon by an earlier modality, are not intended to suggest that the elements, characteristics, and aspects of the modality introduced by the phrase are limited to the previous modality; rather, the phrase is provided to aid the reader in understanding the various elements, features, and aspects disclosed herein and it is to be understood that those skilled in the art will recognize that such elements, features, and aspects presented in the introduced embodiment may be applied. in combination with other various combinations and sub-combinations of the elements, features, and aspects presented in the disclosed embodiments. It should be appreciated that persons of ordinary skill in the art, after considering the descriptions of the present invention, will recognize that various combinations or sub-combinations of the various embodiments and other elements, features and aspects may be desirable, in particular, implementations or applications. . However, because such other elements, features and aspects can be readily determined by persons of ordinary skill in the art after considering the description of the present invention, and it is not necessary for a complete understanding of the disclosed embodiments, a description of such elements, features and aspects may not be provided. Accordingly, it is to be understood that the description presented herein is merely exemplary and illustrative of the disclosed embodiments and is not intended to limit the scope of the invention as defined solely by the claims.

[00038] All numerical quantities indicated herein are approximate unless otherwise indicated, meaning that the term "about" may be inferred where not expressly indicated. The numerical amounts presented in the present invention are not to be understood as not being strictly limited to the exact numerical values mentioned. Instead, unless otherwise noted, each numeric value is intended to mean both the mentioned value and a range of functionally equivalent values around that value. At the very least, and not in an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be interpreted, at least, in light of the number of significant figures reported and through the application of common rounding techniques. However, approximations of numerical quantities given herein, numerical quantities described in specific examples of actual measured values are reported as accurately as possible.

[00039] All numeric ranges listed here include all sub-ranges contained therein. For example, a range of "1 to 10" is intended to include all sub-ranges between and including the minimum stated value of 1 and the maximum stated value of 10. Any maximum numerical limitation referred to herein is intended to include all the lower numerical limitations. Any minimum numerical limitations referred to herein are intended to include all higher numerical limitations. Additionally, in some illustrative embodiments, a parameter, measurement, deviation, or range may be given. It is to be understood that any such parameter, measurement, deviation, or range is provided as an illustrative example or instance of one embodiment and is not intended to limit that or other embodiments.

[00040] As generally used herein, the terms "proximal" and "distal" generally refer to a physician manipulating one end of an instrument used to treat a patient. The term "proximal" generally refers to the portion of the instrument closest to the physician. The term "distal" generally refers to the portion located furthest from the physician. It should also be noted that, for accuracy and clarity, spatial terms such as "vertical". "horizontal", "upwards" and "downwards" may be used in the present invention with respect to the illustrated embodiments. However, surgical instruments can be used in many orientations and positions, and these terms are not intended to be limiting and absolute.

[00041] As generally used herein, the term "ablation" generally refers to the removal of cells directly or indirectly by supplying energy within an electrical field and may include removal by loss of function. cell, cell lysis, necrosis, apoptosis, and/or irreversible electroporation. "Ablation" can similarly refer to the creation of a lesion by ablation. Additionally, the terms "undesirable tissue," "target cells," "diseased tissue," "diseased cells," "tumor," "cell mass" and the like are generally used throughout to refer to cells removed or to be removed, in whole or in part, by ablation and are not intended to limit the application of the systems, devices, or methods described herein. For example, such terms include the ablation of both diseased cells and certain surrounding cells, although there is no definitive indication that such surrounding cells are diseased. Terms similarly include the ablation of cells located around a biological lumen such as a vascular, ductal, or tract area, for example, to create a margin for a surgeon to resect additional cells by ablation or another method.

[00042] In accordance with certain embodiments, an ablation system generally comprises first and second electrodes coupled to an operating power source to generate an electric field between the first and second electrodes when such electrodes are placed in contact with the tissue and energized. An electric current supplied to the electric field is conducted between the first and second electrodes through the tissue. Without wishing to be bound by any particular theory, electric current is believed to propagate through conductive tissue at least partially via electron and/or electrolytic carriers. Electrical ablation devices may generally comprise one or more electrodes configured to be positioned on or close to unwanted tissue (e.g. target cells, target site, treatment site, diseased tissue, diseased cells, tumor, cell mass ) in a tissue treatment region (e.g. a target region). In general, the electrodes may comprise an electrically conductive portion (eg, medical grade stainless steel, gold-plated, etc.) and may be configured to electrically couple to a power source. When positioned on or near the unwanted tissue, an energizing potential can be applied to the electrodes to create an electrical field to which the unwanted tissue is exposed. The energizing potential (and the resulting electric field) can be characterized by various parameters, such as frequency, amplitude, pulse width (duration of a pulse or pulse length), and/or polarity. Depending on the desired application, e.g. the diagnostic or therapeutic treatment to be provided, a particular electrode may be configured as an anode or a cathode, or a plurality of electrodes may be configured with at least one electrode configured as an anode and at least another electrode configured as a cathode. Regardless of the initial polarity setting, the polarity of the electrodes can be reversed by reversing the polarity of the power source output. In some embodiments, an exogenous electrolyte may be applied to the tissue prior to ablation to increase conductivity. In certain embodiments, application of an exogenous electrolyte can increase or decrease an effective area or density of an electric field.

[00043] In certain embodiments, a suitable power source may comprise an electrical waveform generator. The power source generates an electric field having a suitable characteristic waveform output in terms of frequency, amplitude, pulse width, and polarity. The electrodes can be energized with DC voltages and conduct currents at various frequencies, amplitudes, pulse widths, and polarities. The electrodes can also be energized with time-varying voltages and currents at appropriate amplitudes and frequencies to provide the desired therapy. A suitable power source may comprise an electrical waveform generator adapted to apply DC and/or time-varying energizing potentials characterized by frequency, amplitude, pulse width, and/or polarity to the electrodes. Electrical current flows between the electrodes and through the tissue in proportion to the potential (eg, voltage) applied to the electrodes. In various embodiments, the electrical current supplied is provided by the power source and comprises a pulse sequence applied to tissue. For example, a power source may provide multiple waveforms in one or more pulse sequences specific to the desired application. Commonly owned US Patent Application No. 13/036,908, filed February 28, 2011, entitled "ELECTRICAL ABLATION DEVICES AND METHODS," and US Patent Application No. 13/352,495, filed January 18, 2012 , entitled "ELECTRICAL ABLATION DEVICES AND METHODS," disclose many such waveforms, pulse sequences, and methods of applying the same for electrical ablation treatment, the contents of which are incorporated herein by reference.

[00044] In one embodiment, the power source may be configured to produce RF waveforms at predetermined frequencies, amplitudes, pulse widths, and/or polarities suitable for thermal heating and/or electrical ablation of cells in the region of fabric treatment. An example of a suitable RF power source might be a conventional commercially available bipolar/monopolar electrosurgical RF generator, model number ICC 350, available from Erbe, GmbH. In one embodiment, the power source may comprise a microwave power source configured to produce microwave waveforms at predetermined frequencies, amplitudes, pulse widths, and/or polarities suitable for thermal heating and/or electrical ablation of cells in the tissue treatment region. A microwave power supply such as MicroThermx, available from Boston Scientific Corp., can be attached to a microwave antenna that provides microwave power in the 915 MHz to 2.45 GHz frequency range.

[00045] In one embodiment, the power source may be configured to produce destabilizing electrical potentials (eg, fields) suitable for inducing irreversible thermal heating and/or electroporation. Destabilizing electrical potentials can be in the form of single-phase bipolar/monopolar electrical pulses suitable for inducing irreversible thermal heating and/or electroporation. A commercially available power source suitable for generating electrical field pulses for thermal heating and/or irreversible electroporation in bipolar or monopolar mode is a pulsed DC generator model number ECM 830, available from BTX Molecular Delivery Systems Boston, MA, USA. In bipolar mode, the first electrode may be electrically coupled to a first polarity and the second electrode may be electrically coupled to a second (e.g. opposite) polarity of the power source. Bipolar/monopolar single-phase electrical pulses can be generated at a variety of frequencies, amplitudes, pulse widths, and/or polarities. Unlike RF ablation systems, which may require high levels of power and energy applied to tissue to heat and thermally destroy tissue, irreversible electroporation may require very little energy applied to tissue to heat and kill unwanted tissue cells with the use of electric field potentials instead of heating. Consequently, irreversible electroporation systems can avoid the harmful thermal effects caused by RF ablation systems.

[00046] Various embodiments of the systems, devices, and electrical ablation methods described herein use electroporation or electropermeabilization techniques to apply external electric fields (electrical potentials) to cell membranes to significantly increase the permeability of the cell's plasma membrane. Irreversible electroporation (EIR) is the process of killing cells by increasing the electrical potential across the cell membrane over a long period of time. EIR provides an effective method of destroying cells while avoiding some of the negative complications of heat-inducing therapies. Namely, EIR kills cells without raising the temperature of the surrounding tissue to a level at which permanent damage can occur to the supporting structure or regional vasculature. Large destabilizing EIR electrical potentials can be in the range of about several hundred to about several thousand volts applied to tissue to increase the local electric field. The increase in the electric field will increase the membrane potential over a distance of about several millimeters, for example, for a relatively long period of time. The destabilizing electrical potential forms pores in the cell membrane when the potential across the cell membrane reaches a critical level causing the cell to die by processes known as apoptosis and/or necrosis.

[00047] The application of RIE pulses to cells can be an effective way to ablate large volumes of unwanted tissue with no or minimal harmful thermal effects to the surrounding healthy tissue. Thus, in some embodiments, the EIR may be used in conjunction with the various electrodes and/or other electrical ablation devices disclosed herein to perform one or more minimally invasive surgical procedures or treatments. Without wishing to be bound by any particular theory, it is believed that EIR destroys cells with no or minimal heat, and thus, may not destroy cellular support structure or regional vasculature. A destabilizing irreversible electroporation pulse, suitable for causing cell death without inducing a significant amount of thermal damage to surrounding healthy tissue, can have amplitudes in the range of several hundred to several thousand volts and can generally be applied via biological membranes over a distance of several millimeters, for example for a relatively long duration of 1 μs to 100 ms. In this way, unwanted tissue can be ablated in vivo through the application of destabilizing electric fields, rapidly causing cell necrosis.

[00048] In certain embodiments, the power source may comprise a wireless transmitter to apply power to the electrodes using wireless power transfer techniques via one or more remotely positioned antennas. Those skilled in the art will appreciate that wireless power transfer or wireless transmission of power refers to the process of transmitting electrical energy from a power source to an electrical load without interconnecting wires. In one embodiment, the power source may be coupled to the first and second electrodes by a wired connection or a wireless connection. In a wired connection, the power source can be coupled to the electrodes via electrical conductors. In a wireless connection, the electrical conductors can be replaced with a first antenna coupled to the power source and a second antenna coupled to the electrodes, where the second antenna can be remotely located from the first antenna. In one embodiment, the power source may comprise a wireless transmitter to apply power to the electrodes using wireless power transfer techniques via one or more remotely positioned antennas. As previously discussed, wireless power transfer or wireless power transmission is the process of transmitting electrical energy from the power source to an electrical load, e.g. abnormal cells in the tissue treatment region, without using electrical conductors. of interconnection. An electrical transformer is the simplest example of wireless power transfer. The primary and secondary circuits of a transformer may not be directly connected and energy transfer may occur by electromagnetic coupling through a process known as mutual induction. Power can also be transferred wirelessly using RF energy.

[00049] As will be noted, electrical ablation devices, systems, and methods may comprise portions that can be inserted into the tissue treatment region percutaneously (e.g., where access to internal organs or other tissue is via needling perforation). of the skin). Other portions of electrical ablation devices may be introduced into the tissue treatment region endoscopically (e.g., laparoscopically and/or thoracoscopically) through trocars or endoscope channels, through small incisions, or transcutaneously (e.g., where electrical pulses are applied to the tissue treatment region through the skin).

[00050] Systems, devices, and methods for electrical ablation therapy can be adapted for use in minimally invasive surgical procedures to access tissue treatment regions at various anatomical sites, such as the brain, lungs, breast, liver , gallbladder, pancreas, prostate gland, and various internal bodies or biological lumens (e.g., a natural bodily orifice) defined by the esophagus, stomach, intestine, colon, arteries, veins, anus, vagina, cervix, fallopian tubes fallopian tube, and the peritoneal cavity. Minimally invasive electrical ablation devices can be introduced into the tissue treatment region although a small opening formed in the patient's body with the use of a trocar or through a natural bodily orifice such as the mouth, anus, or vagina with the use of transluminal access techniques known as Natural Orifice Translumenal Endoscopic Surgery (NOTES)™ in which electrical ablation devices can be initially introduced through a natural body orifice and then advanced to the tissue treatment site by perforating the walls of the lumen of the internal body. In various embodiments, the electrical ablation system can be adapted to treat unwanted tissue in the brain, lung, breast, liver, gallbladder, pancreas, or prostate gland, using one or more electrodes positioned percutaneously, transcutaneously, transluminally. , minimally invasively, and/or through open surgical techniques, or any combination thereof.

[00051] In certain embodiments, systems, devices, and methods may be configured for the treatment of minimally invasive ablation of masses, tumors, cell growths, or other unwanted tissue. Minimally invasive ablation of unwanted tissue treatment may be characterized by the ability to reduce trauma by precisely targeting unwanted tissue through one or more biological lumens (e.g., a natural bodily orifice, vascular area, duct, or tract) and applying an electrical field to excise the unwanted tissue in a controlled and focused manner while at the same time retaining the cellular infrastructure of the healthy surrounding tissue. In accordance with various embodiments, applying an electrode to a biological lumen and placing the electrode in contact with the lumen wall in a controlled manner provides increased electroablative accuracy that can reduce unwanted lesions, increase the likelihood of desirable circumferential ablation zones, and/or or attach the necessary infrastructure to the surrounding tissue. For example, the uniformity and/or density of an electric field over particular regions of the electric field established by various electrodes and/or returns can be more precisely focused or controlled. In certain embodiments, contacting the electrode with a wall of the lumen in a controlled manner comprises circumferentially contacting the electrode with the wall of the lumen at two or more locations around the circumference of the wall at or near a treatment site, for example, at or along two locations around the circumference of the wall separated by 15°, 30°, 90°, or 180°, for example. Such contact may be continuous, such as contact connecting two points, or discontinuous, such as contact at a first point and at a second point without contact along at least an intercalated portion of the lumen wall between the first and second points.

[00052] When a tissue treatment region is located in or near a biological lumen, such as a vascular, duct, cavity, orifice, or tract area, e.g., minimally invasive electrical ablation devices that comprise electrodes may be applied to the tissue treatment region through an artificial lumen (e.g., endoscope channel, sheath, sleeve, trocar) and/or through one or more biological lumens, as described herein. In various embodiments, an electrical ablation device (e.g., electrode or an electrode disposed along a probe comprising an elongate element) may be fed through the biological lumen into an endoscope, trocar, sheath, sleeve, or channel. for example. An electrical ablation device can also be configured to be powered through a biological lumen "without anything," that is, without assistance from the above instruments. For example, an electrode can be configured to be flexibly powered or directed through one or more biological lumens to the treatment region. In some embodiments, electrodes may be provided along a distal portion of an elongate member comprising a probe. The elongate element may thus be configured to deliver one or more electrodes to a region of tissue. Portions of the elongate element proximal to an electrode may respond to signals from a physician directing one or more such positions along a length of the elongated element to move. For example, an elongated element may be responsive to signals to flex in one or more positions along its length during application to a region of tissue. When electrical ablation devices (eg, electrodes) are applied or located on or close to unwanted tissue in the treatment region, electrodes can be installed to contact lumen tissue and deliver ablative treatment. Such flexion, therefore, may assist in navigation and/or placement of the electrical ablation device through or within a biological lumen during application, placement, or during or after ablative treatment.

[00053] In particular embodiments, the electrodes may be configured to expand circumferentially, for example, when installed or when located in or near undesirable tissue within a region of tissue. Expansion can be the result of positioning, an electrical, mechanical, chemical, or thermal signal that triggers an expansion, or, in some cases, a contraction. In some embodiments, the electrodes can be configured to expand in at least one dimension. For example, electrodes can be configured to expand in diameter. The electrodes can also be configured to expand in length, such as extending a length of the electrode. In some embodiments, an extension in length may be independent of an expansion in diameter. For example, electrodes can expand in length without expanding in diameter, or they can expand in diameter without expanding in length. In other embodiments, however, an expansion in diameter or length may be concomitant with an increase or decrease in diameter or length. In certain embodiments, electrodes can be configured to expand in diameter or length only. In various embodiments, the electrodes expandable in one or more dimensions may be similarly configured to contract in one or more dimensions. Such electrodes can be said to be transitionable between an expanded state and a contracted state. In some embodiments, transitions between one or more expanded states and one or more contracted states may be in response to a signal provided by a physician. Thus, in some embodiments, a physician may selectively transition an electrode to a desired expanded and/or contracted state to beneficially adjust an electrode to a desired application, such as a procedure and/or biological structure. In certain instances, selecting an expanded state can provide an increase in contact about a circumference of a lumen thus creating a more precisely defined electric field and increasing the controllability of electric field potentials, for example. In various embodiments, an electrode may comprise an antenna, such as a microwave antenna, wherein unwanted tissue positioned adjacent to or close to the antenna may be more completely exposed to ablative energy when the electrode is in an expanded state compared to a contracted state. For example, a diameter, length, and/or surface area of an electrode comprising antenna can be increased in the expanded state such unwanted tissue is completely exposed to ablative energy.

[00054] An electrical ablation system 10 incorporating an electrical ablation device 12 according to one embodiment is illustrated in Figure 1 and includes an elongate element 18 having disposed along it a connector 19 configured to mate with a power source. power 11, a cable 14, a first electrode 21 (not shown), and a distal tip 28. The cable 14 is configured to provide a physician with a manipulation point to, for example, manipulate and/or maneuver the elongate element 18 The elongate element 18 includes a conductive structure comprising a lead wire 17 through which power can be transmitted between the connector 19 and the first electrode 21. It should be appreciated, however, that in some embodiments the elongate element 18 or electrode 21 may be wirelessly coupled to power source 11 or may be coupled to power source 11 by various methods known in the art. Cable 14 includes a sheath 40 extending from a distal end thereof through a protective sleeve 38. In the illustrated embodiment, cable 14 and sheath 40 define a channel 15 through which the conductive structure extends. Sleeve 38 may comprise an insulating material, such as heat shrink, for example, and may be attached to cable 14. As illustrated, sheath 40 comprises a flexible insulator such as a non-conductive material by which electrical current can be insulated. As is to be understood, respective lengths of the elongate element 18 and/or the sheath 40 will more generally depend on the desired application; therefore, the lengths illustrated here are not intended to be drawn to scale.

[00055] In Figure 1, the first electrode 21 (not shown) is in a retracted or unmounted position and is received within the sheath 40. In various embodiments, the distal portion of the elongate element 18, including the sheath 40, may be configured as an application platform from which the first electrode 21 can be manipulatively applied to a treatment region and subsequently installed to a treatment site. Accordingly, cable 14 may include an actuator configured to implant the first electrode (not shown). In the illustrated embodiment, the handle 14 includes an actuator comprising a sliding member 30 configured to be slidable through an opening 32 and is coupled to a sliding assembly 34 comprising a piston 35 which is translatable through a cylinder 36 defined within the handle 14. Slider assembly 34 is operatively coupled to elongate member 18 such that movement of slider member 30 retracts or advances distal portion of elongate member 18 with respect to distal end of handle 14. In this embodiment, sheath 40 it is fixed with respect to the distal end of the handle 14. However, in certain embodiments, the sheath 40 may be movable relative to the distal end of the handle 14 with the use of an actuator, such as the sliding member 30, for example. The distal portion of the elongate element 18 may be applicable to a tissue treatment region, for example, physically advancing the elongate element 18, such as feeding the elongate element 18 into a patient within the sheath 40, artificial lumen, natural orifice, or lumen. biological. In some embodiments, one of which is illustrated in Figure 2, the elongate element 18 may be advanced to implant and expose the first electrode 21 beyond the distal end of the handle 12, sheath 40, endoscope (not shown), or other delivery device. (eg a channel). In certain embodiments, the elongate member 18 may also be retracted from the distal end of the handle 14, sheath 40, endoscope (not shown), or other delivery device. As shown in Figures 1 and 2, a physician may reposition slider member 30 to selectively extend and retract elongate member 18 with respect to the distal end of sheath 40. For example, distally positioning slider member 30 extends elongate member 18 in relative to the distal end of the sheath, exposing the first electrode 21, and subsequently repositioning the sliding member 30 proximally retracts the elongate member 18 relative to the distal end of the sheath, receiving the first electrode 21 within the sheath 40.

[00056] The electrical ablation system 10 illustrated in Figure 1 further comprises a second electrode 22 coupled to the power source 11. In this particular embodiment, the second electrode 22 comprises a return block. In various embodiments, the second electrode 22 may be a return block, needle, claw, second elongate element, or second electrode disposed along the distal portion of elongate element 18. Notably, those skilled in the art will observe that the optimal type of second electrode 22 will generally be dependent on the desired application of the system 10.

[00057] In some embodiments, electrodes 21, 22 can deliver electrical field pulses to unwanted tissue. Such electric field pulses can be characterized by various parameters, such as pulse shape, amplitude, frequency, pulse width, polarity, total number of pulses and duration. In various embodiments, electric field pulses may be sufficient to induce thermal heating in the unwanted tissue without inducing irreversible electroporation in the unwanted tissue. In certain embodiments, electric field pulses may be sufficient to induce irreversible electroporation in unwanted tissue. The induced effects may depend on a variety of conditions, such as tissue type, cell size, and electric field pulse parameters. For example, the transmembrane potential of a specific tissue type may mainly depend on the electric field amplitude and pulse width.

[00058] In one embodiment, the input to power supply 11 may be connected to a commercial power supply via a plug (not shown). The output of power source 11 is coupled to electrodes 21, 22, which can be energized using an activation switch (not shown) on lead 14, or an activation switch mounted on an activated foot pedal (not shown) . The power source 11 can be configured to generate electrical pulses at a predetermined frequency, amplitude, pulse width, and/or polarity which are suitable for inducing unwanted tissue thermal heating in the treatment region or inducing irreversible electroporation to excise substantial volumes of unwanted tissue in the treatment region. The polarity of the DC pulses can be reversed or inverted from positive-to-negative or negative-to-positive a predetermined number of times to induce irreversible electroporation to excise substantial volumes of unwanted tissue in the treatment region.

[00059] In some embodiments, one or more of a series of electrical pulses may be applied to induce RIE. In one embodiment, a timing circuit may be coupled to the output of power source 11 to generate electrical pulses. The timing circuit may comprise one or more switching elements suitable for producing the electrical pulses. For example, power source 11 can produce a series of m electrical pulses (where m is any positive integer) of sufficient amplitude and duration less than the necrotic threshold to induce undesirable tissue thermal heating when the m electrical pulses are applied. and a series of n electrical pulses (where n is any positive integer) of sufficient amplitude and duration to induce irreversible electroporation suitable for tissue ablation when the n electrical pulses are applied. In various embodiments, the electrical pulses may have a fixed or variable pulse width, amplitude, and/or frequency.

[00060] The electrical ablation device 12 can be operated in bipolar mode, e.g. electrodes are relatively close together, or monopolar mode, e.g. electrodes are too far apart and an electrode typically has a much larger surface area . For example, electrodes 21, 22 can be used in a bipolar electrical ablation system where the first electrode 21 has a positive polarity with respect to the other electrode 22. In monopolar mode, a grounding block, as illustrated in Figure 1, for example, it may be substituted for one of the electrodes 21, 22. In some embodiments, the second electrode 22 comprises one of an electrode disposed along the elongate element 18, an electrode disposed along a second elongate element, a needle electrode , or a claw. In some embodiments, electrodes 21, 22 may be used in a two-phase electrical ablation system in which the polarity of each electrode 21, 22 alternates. In biphasic mode, the first electrode 21 can be electrically connected to a first polarity and the second electrode 22 can be electrically connected to the opposite polarity. In monopolar mode, the first electrode 21 can be coupled to a prescribed voltage and the second electrode 22 can be grounded. The power source 11 can be configured to operate in a biphasic or single-phase mode with the electrical ablation system 10. In bipolar mode, the first electrode 21 can be electrically connected to a prescribed voltage of one polarity and the second electrode 22 can be electrically connected to a prescribed voltage of opposite polarity. When more than two electrodes are used, the polarity of the electrodes can be switched so that any two adjacent electrodes can have the same or opposite polarities.

[00061] Again with reference to Figure 2, the first electrode 21 includes an expandable portion 20 expandable in at least one dimension. In particular, the expandable portion 20 illustrated in Figure 2 includes an expanded diameter compared to the diameter of the expandable portion 20 when received within the sheath 40. When received within the sheath 40, the sheath 40 defines a channel having a diameter greater than that. of the received expandable portion 20. However, when installed from the sheath 40 and expanded, as illustrated in Figure 2, the expandable portion 20 is expanded so that the diameter of the expandable portion 20 is greater than that of the channel defined within the sheath 40. Accordingly, when received, the expandable portion 20 is in a contracted state and when installed and/or expanded the expandable portion 20 is in an expanded state.

[00062] In various embodiments, the elongate element 18 may be flexible along all or a portion of its length. Such flexible portions may be flexible, deformable, or elastic, for example. The flexible portions may also be conditionally flexible or conditionally rigid, for example. In some embodiments, the elongate element 18 comprises flexible portions that can be mechanically flexible so that the portions of the elongate element 18 are pivotable in response to a signal or otherwise manipulable. In some embodiments, the elongate element 18 may be proximally and/or distally advanced with respect to the handle 14. A distal advance of the elongate element 18 relative to the distal end of the handle 14, for example, may coincide with a distal advance of the elongate element. 18 relative to the proximal end of the handle 14. In certain embodiments, advancing the elongate element 18 increases a length of the elongate element 18, distal to the distal end of the handle 14, the increase in length coincides with a decrease in length of the elongate element 18 proximal to the proximal end of the handle 14. In various embodiments, a proximal advancement of the elongate element 18 relative to the distal end of the handle 14 coincides with a proximal advance of the elongate element 18 relative to the proximal end of the handle 14. In certain embodiments, while advancing the elongate element 18 decreases a length of the elongate element 18 distal to the distal end of the handle 14, the decrease in length coincides with an increase in length of the elongate element 18 proximal to the proximal end of the handle 14. Although the elongate element 18 illustrated in Figure 1 is shown to have a general cylindrical shape, it should be appreciated that the elongate element 18 may have any suitable shape or section. cross. For example, cross-sections of the elongated element 18 or portions thereof may generally be defined as circular, triangular, rectangular, pentagonal, hexagonal, or any of the suitable delimited shapes, whether a regular or irregular geometric shape, for example. example.

[00063] In some embodiments, one or more portions of the elongate element 18 may be spirally wound, nested, or otherwise contained within the handle 14 or a distal portion of the elongate element 18. In some such embodiments, a distal advancement of the elongate element 18 relative to the distal end of the handle 14 does not coincide with a distal advancement of the elongate element 18 relative to the proximal end of the handle 14. In such an embodiment, a proximal advance of the elongate element 18 relative to the distal end of the handle 14 does not coincide with a proximal advancement of the elongate element 18 relative to the proximal end of the handle 14. In certain embodiments, advancing the elongate element 18 increases a length of the elongate element 18 distal to the distal end of the handle 14, the length of the elongate element 14 18 proximal to the proximal end of handle 14 remains the same. In such an embodiment, when advancing the elongate element 18 decreases a length of the elongate element 18 distal to the distal end of the handle 14, the length of the elongate element 18 proximal to the proximal end of the handle 14 remains the same.

[00064] In certain embodiments, the electrical ablation system 10 comprises a relatively flexible elongated element 18 and may be introduced, directed, and applied to a tissue treatment region within the sheath 40. The sheath 40 may be a hollow hole, like a tube, for example. In some embodiments, the sheath 40 is semi-rigid and can be used to precisely apply the first electrode 21 to a tissue treatment region. The elongate element 18 is translatable through the hollow hole to alternately retract and implant one or more electrodes 21, 22 or a portion thereof. In some embodiments, the elongate member 18 comprises an extendable portion, such as an extendable length. The length may be extensible by, for example, extending the elongate element 18 distally so that the elongate element 18 extends distally with respect to the distal end of the handle 14, thereby advancing or installing the first electrode 21 or a portion thereof. Similarly, an actuator such as slide assembly 34 may be provided to extend the elongate element 18. For example, the elongate element 18 may advance or implant the first electrode 21 or a portion thereof by distally feeding an additional length of the elongate element. 18. It should be appreciated that the extension of the elongate element 18 is not limited to feeding the additional elongate element 18 distally from the handle 14. In some embodiments, a portion of the elongate element 18 may extend by moving a first portion of the elongate element 18 in relative to a second portion of the elongate element 18. The first and second portions of the elongate element 18 may flank either side of a nested portion so that relative movement between the first and second portions of the elongate element 18 can thus result from a telescopic extension or retraction of a length of the elongate element 18, increasing or decreasing the overall length of the elongate element 1 8. The first and second portions of the elongate element 18 may also flank both sides of a bent portion of the elongate element 18 so that relative movement between the first and second portions of the elongate element 18 can thus result from a bending or unfolding of the bent portion resulting in an accordion-shaped extension or retraction of a length of the elongate member 18. Relative movement between the first and second portions can be achieved by any known mechanism, such as pulleys, reciprocating extension members, sliding crimps, gears, and/or rails, for example. In some embodiments, the elongate element 18 may advance or implant the first electrode 21 by progressively releasing an incline into the elongate element 18. In the embodiment illustrated in Figure 1, an actuator is configured to implant the first electrode 21 from the distal end of the sheath. 40. However, in other embodiments, a sheath 40 may not be provided and the clinician may implant the first electrode 21 by advancing the first electrode 21 from the distal end of an endoscope, trocar, or other artificial lumen configured to receive the elongate element 18 and deliver the first electrode 21 to the target region. In these and other embodiments, the sheath 40 or artificial lumen may be configured to implant or withdraw the first electrode 21 or portion thereof by advancing or retracting to expose or receive the first electrode 21 or portion thereof.

[00065] As previously described, the elongate member 18 may comprise a distally located tip 28. In certain embodiments, the tip 28 may include an insulator configured to resist the conduction of electrical current. It should be appreciated that tips 28 of various dimensions can be supplied to suit particular applications. For example, in some embodiments, the length of the tip 28 can be longer than the first electrode 21 while in other embodiments the length of the tip 28 can be shorter than the first electrode 21. The tips 28 of various lengths can, beneficially, increase the stability of the first electrode 21 during ablation or assist in the application of the first electrode 21 by increasing, for example, the orientability of the elongate element 18. In various embodiments, a diameter of the tip 28 can be greater than or less than a diameter of the first electrode 21 in a contracted state. In some such embodiments, the tip 28 may comprise multiple diameters. Tips 28 comprising multiple diameters can be configured to aid in the application, placement, and/or positioning of the first electrode 21. For example, contours provided around the multiple diameters of the tip 28 can be designed to anchor or snugly position the first electrode 21. at or near a treatment site. Such contours may also include one or more surface features configured to gripperly engage the fabric at or near a treatment location. In various embodiments, the tip 28 comprises a distal end configured to aid in the application, placement and/or positioning of the first electrode 21. For example, a distal end of the tip 28 may comprise a blunt or stray end, as illustrated in Figure 1, for example. In some embodiments, the distal end of the point 28 comprises a comparatively sharp point configured to direct the elongate member 18 along the surfaces and into the grooves. Figure 3 illustrates an embodiment comprising such a tip 28. In particular, Figure 3 illustrates a first electrode 21 disposed along a distal portion of the elongate member 18. The distal end of the elongate member 18 comprises a tip 28. The tip 28 it is tapered to a comparatively sharp point. It should be noted that the degree of funneling may be higher or lower than that shown in Figures 1 or 3, depending on the desired application. In some embodiments, the tip 28 may be a sharp point configured to pierce tissue and/or anchor the first electrode 21. The tip 28 may also comprise a thin catheter configured to drain fluid, for example. As will be explained in more detail below, in certain embodiments, the tip 28 may perform any number of functions such as sensory functions (e.g., optical elements, temperature, location, etc.) and/or electrolyte delivery. It should be noted that in some embodiments an electrode 21 may comprise tip 28 and be configured to supply or receive electrical current. For example, in some embodiments, tip 28 may be a needle electrode.

[00066] In various embodiments, the slider assembly 34 is operatively coupled to the sheath 40 such that movement of the slider member 30 in a first direction advances the sheath 40 with respect to the distal end of the handle 14 and the movement of the slider member 30 in a second direction retracts the sheath with respect to the distal end of the cable 14. In some embodiments, the sheath may be retractable with respect to the distal end of the cable 14 to expose or apply the first electrode 21 to a position installed at or close to it. a treatment site. In some embodiments, sheath 40 may be advanceable with respect to the distal end of handle 14 to engage or withdraw first electrode 21 to a retracted position. It will be understood that the elongate element 18 may be advanceable by arrangements in addition to the sliding member 30, such as a lever, actuator, actuator, or button, for example, and advancement or retraction may be effected manually, electrically, and/or mechanically, for example. . In one embodiment, the elongate element 18 may be advanced or retracted by increasing or decreasing a length of the elongate element 18. For example, one or more electrodes 21 or other portions of the elongate element 18 may comprise an adjustable length comprised of an elastic band. or otherwise extensible or compressible so that a length adjustment effects advancement or retraction of the elongate element 18. In some embodiments, a distal advancement of the elongate element 18 implants the first electrode 21 to the target tissue and a proximal retraction of the elongate element 18 18 removes the first electrode 21 from the target tissue. In some embodiments, one or more actuators may be configured to implant the first electrode 21 into a treatment region, to withdraw the first electrode 21 from a treatment region, to extend or flex the first electrode 21, and/or to transition the expandable portion 20 between contracted and expanded states. In some embodiments, multiple transitions can be triggered by the same actuator or by different actuators. For example, an actuation signal to transition between a contracted state and an expanded state can be coupled with an actuation signal to withdraw or implant the first electrode 21.

[00067] In various embodiments, the first and second electrodes 21, 22 may be disposed along the distal portion of the elongate element 18 and may be used to more precisely define a treatment area to, for example, ablate unwanted tissue. while reducing muscle contractions in contiguous tissues. Figure 4 illustrates an embodiment of the electrical ablation device 12 and system 10 shown in Figure 1 comprising a first electrode 21 and a second electrode 22 disposed along the distal portion of the elongate element 18. The first electrode 21 may be configured as the positive electrode and the second electrode 22 can be configured as the negative electrode. The first electrode 21 may be electrically coupled to the conductive structure, which may be coupled to the positive terminal of the power source 11. The second electrode 22 may be electrically coupled to a conductive structure, such as an electrically conductive cable or wire, which may be coupled to the negative terminal of the power source 11. The conductive structures may be electrically insulated from each other and surrounding structures, except for electrical connections to the respective electrodes 21, 22. The first and second electrodes 21, 22 may be installed using actuation methods similar to those described in connection with the first electrode 21. For example, the first electrode 21 may be withdrawn or advanced by repositioning the sliding member (not shown) or other actuator. The second electrode 22 may similarly be withdrawn or advanced by repositioning the same sliding member or a different sliding member or other actuator. In some embodiments, advancing the first electrode 21 or the second electrode 22 implants respective electrodes 21, 22 from the distal end of the sheath 40. One or both of the electrodes 21, 22 may be attached to the sliding member, or additional sliding members may be provided to advance and/or remove the electrodes 21, 22 and/or to implant the electrodes 21, 22. Additionally, it must be considered that, in certain modalities, the first and second electrodes 21, 22 may be selectively amenable to positioning. In this way, a physician can optionally use the first electrode 21 or the second electrode 22 by selectively implanting only the first electrode 21 or only the second electrode 22. In this regard, the physician can independently locate additional electrodes before or after applying energy to the first electrode 21. and/or second electrode 22, thereby providing flexibility to create a variety of electrical fields during a single insertion of electrical ablation device 12. It should be noted that, in some embodiments, the identities of first electrode 21, second electrode 22 , or additional electrodes can be selectively altered or exchanged. For example, in one embodiment, the functionality of the first electrode 21 may be disabled and the identity of the second electrode 22 changed to the previous identity of the first electrode 21.

[00068] In some embodiments, where the elongated element comprises multiple electrodes, the distance "d" between the electrodes may be adjustable. Referring again to Figure 4, the illustrated embodiment includes an adjustable distance between the first electrode 21 and the second electrode 22. Such an adjustable distance may be adjustable between 2 mm and 25 mm, for example, and may be used to flexibly confine a zone of treatment. A physician can therefore adjust the distance "d" between the electrodes 21, 22 prior to use by inserting, for example, one or more extenders or inserts between the electrodes 21, 22. Multiple extenders or inserts of suitable lengths may be provided to allow a clinician to customize the distance between the electrodes 21, 22 and adapt the length to a desired use. In some embodiments, the distance between electrodes 21, 22 may be adjusted by advancing or rotating the first electrode 21 with respect to the second electrode 22 by actuation of one or more sliders or actuators located on the handle 14. For example, electrodes 21, 22 22 can be threaded or slidably arranged along the elongate element about threads or along another track. In various embodiments, the interleaved length of elongated element between electrodes 21, 22 can expand thereby increasing the distance.

[00069] Figure 5 illustrates a further embodiment of the electrical ablation device 12 and system shown in Figure 1 comprising a first electrode 21 and a second electrode 22 disposed along the distal portion of the elongate element 18. The electrodes 21, 22 are illustrated in various levels of expanded states. For example, both the first electrode 21 and the second electrode 22 are expanded around the axis. The second electrode 22, however, is also extended along the axis and comprises a longer length than the first electrode 21. In some embodiments, asymmetrical electrodes may be provided so that when the electrodes 21, 22 expand, the electrodes 21, 22 comprise divergent dimensions. In other embodiments, however, symmetrical electrodes (eg, electrodes comprising the same or substantially similar dimensions) may be provided. The divergent dimensions may include, for example, different diameters and/or lengths, as illustrated in Figure 5. The selection of optimal divergent dimensions with respect to two or more electrodes 21, 22 will, in general, be determined by the desired application. Notably, and as will be explained in more detail below, the first 21 and second electrodes 22 may diverge in one or more dimensions as a result of selective expansion, as a by-product of an expansion method, or due to construction. For example, the length of the first electrode 21 in the contracted state may or may not be the same length as the second electrode 22 in the contracted state, however, the length of the two electrodes 21, 22 may nevertheless be the same length in respective states. expanded. The embodiment illustrated in Figure 5 further comprises a third electrode 23 disposed along the distal portion of the elongate element 18. The third electrode 23 is distal to the first electrode 21 and, in some embodiments, may be attachable to the first electrode 21 in a connection. at or near the distal tip 28 of the elongate element 18 or first electrode 21. In some embodiments, the third electrode 23 is configured as a return or comprises a different polarity than the first 21 and/or the second electrode 22. In other embodiments, however, the third electrode 23 is configured to extend the electrical identity of the first 21 or the second electrode 22.

[00070] In accordance with the various embodiments of electrical ablation systems, devices, and methods disclosed herein, electrodes 21 may comprise flexible and/or expandable portions. In some cases, such flexible and/or expandable portions may include a frame comprising one or more frame members that can provide structure to the flexible and/or expandable portions. In various embodiments, a structure defines a selectively expandable perimeter and/or diameter of the expandable portion and may include one or more energy delivery surfaces configured to contact tissue and deliver ablative energy. In the present invention, the periphery surfaces and generalized shape of expandable and/or flexible portions may generally be referred to as a basket. It should be noted that the electrodes in Figures 2 to 5 and 7 include one or more generalized representations of baskets and, therefore, are not intended to limit the description in relation to the appearance or construction of structures. Notably, as will become evident below, flexible and/or expandable portions may comprise baskets comprising various frame constructions having various perimeters and cross-sections including a helical, circular, triangular, rectangular, pentagonal, hexagonal, or any other section. suitable shape, be it a regular or irregular geometric shape, for example. Furthermore, while, in some embodiments, a frame may comprise, for example, a conductive sleeve having an energy delivery surface configured to apply ablative energy that may or may not be arranged around internally disposed frame members, baskets in various other modalities need not comprise a continuous surface. For example, in certain embodiments, a basket comprises a discontinuous surface defined by a frame of two or more frame members that include tissue contact regions having energy delivery surfaces configured to contact tissue and apply ablative energy. . It should also be considered that although the types of electrodes 21 and portions thereof can be called expandable or flexible, the two are not mutually exclusive. Indeed, in certain embodiments, an electrode 21 comprises a flexible portion and an expandable portion wherein at least a portion of the expandable portion comprises at least a portion of the flexible portion. That is, at least a portion of the expandable portion and the flexible portion of electrode 21 overlap. In some embodiments, however, the expandable portion and the flexible portion may not overlap or may only overlap when electrode 21 is in the contracted or expanded state.

[00071] Frame members may be configured to flex or bend in one or more directions and may comprise flexible materials that exhibit elastic and/or reflective properties. For example, the frame members may comprise materials such as plastics, polymers, alloys, metals, or other elastics including superelastics. Frame members may similarly comprise rigid or conditionally rigid materials configured to flex or bend about a joint or socket, for example. In some embodiments, a clinician can lessen the trauma associated with directing electrodes through tortuous biological lumens using a flexible electrode 21. The flexible electrodes 21 can beneficially reach unwanted tissue in target regions that may otherwise be considered inoperable. In various embodiments, the flexible electrodes 21 may also increase the area of contact between tissue contact regions of the flexible electrodes 21 and unwanted tissue. As those skilled in the art will recognize, flexible electrodes 21 can be especially useful in providing greater control over an application when, for example, unwanted tissue is partially obstructing a biological lumen.

[00072] Figure 6 illustrates a flexible portion 16 in accordance with certain embodiments. Flexible portion 16 is disposed along a distal portion of elongate member 18 and includes a cylindrical frame 50 comprising a spiral wound frame member 52 (e.g., a spring). The frame 50 extends along a longitudinal axis defined by the flexible portion 16. The frame further comprises a proximal coupler 54 and a distal coupler 56. The proximal coupler 54 and distal coupler 56 are configured to couple the frame member 52 to the member. elongate 23 and tip 28. In the illustrated embodiment, the tip 28 provides a blunt, rounded end and the flexible portion 16 is flexibly configured for insertion into a biological lumen so that it can flex or bend, for example, in response to curvatures of the lumen. Electrode 21 may also beneficially bend or flex during application to a tissue treatment region through an artificial delivery channel such as an endoscope, trocar, or lumen, for example, or with nothing (i.e., exposed or not within an artificial application channel). In this regard, the flexible portion 16 can be flexibly applied to a target region in a minimally invasive manner.

[00073] In various embodiments, the electrodes 21 can be expandable in any physical dimension, such as, for example, width or height. In some embodiments, for example, an expansion of an electrode 21 may be described as an increase in a diameter of the electrode 21. As generally used herein, the term "diameter" generally means a distance in line line between two points located along a perimeter of an expandable portion 20 so that the straight line passes through the axis of the expandable portion 20. The perimeter of an expandable portion 20 may comprise a periphery or outer surface of the expandable portion 20. For example, in some embodiments, the frame 50 defines a perimeter of the expandable portion 20 and a diameter can be the distance between two tissue contact regions on opposite sides of the frame. It should be noted that the diameter is not limited to a specific geometric shape or cross-section and includes a helical, circular, triangular, rectangular, pentagonal, hexagonal, or any other suitable shape, whether a regular or irregular geometric shape, for example. .

[00074] In addition to expandability and/or flexibility, an electrode 21 may also be extensible. That is, a length of electrode 21 may be extensible by extending a movable portion of electrode 21 with respect to a fixed portion of electrode 21. For example, in one embodiment of flexible electrode 21 illustrated in Figure 6, a physician may extend the electrode flexible 21 driving relative movement between proximal coupler 54 and distal coupler 56 so that the length of flexible portion 16 increases. Such an extension may or may not reduce the flexibility of the flexible portion 16. As those skilled in the art may recognize, in various embodiments of the electrodes disclosed herein, an extendable length that can be used by a physician increases an area of application to reduce, beneficial, trauma that might otherwise result from multiple ablative treatments.

[00075] In various embodiments, an electrical ablation device 12 comprises one or more expandable electrodes 21. Expandable electrodes 21, such as those illustrated in Figures 2, 3, and 4, for example, may comprise a structure 50 comprising one or more more frame members 52. It should be appreciated that frame members 52 may have a first associated shape and a second associated shape. In some embodiments, the first shape comprises a memory shape and the second shape comprises a retained shape. The retained form may comprise an arrangement or orientation of frame members 52 different from the memory form. For example, in retained form, frame members 52 may be deformed, retarded, or otherwise stretched as a result of manipulation by, for example, a retaining frame. Manipulation may include tension such as torque, compressive, and/or tension in one or more frame members 52 so that the expandable portion 20 comprises an increased or decreased diameter. In some embodiments, manipulation may result in plastic deformation. In certain embodiments, frame members 52 in retained form may be transitioned to memory form by releasing or removing a retaining frame that retains frame members 52 in retained form. In certain embodiments, frame members 52 in retained form may also be returned to memory form by manipulation including applying torque, compression, and/or tensile stress to one or more frame members 52 so that the expandable portion 20 and/or frame 50 comprises an increased or decreased diameter.

[00076] The degree to which a dimension of an expandable portion 20 can expand may be many multiples of the original dimension value. For example, a dimension of an expandable portion 20 in a first state may have a value of 1 and the dimension of an expandable portion 20 in a second state may have a value of 2, 3, 10, 20 or greater, such as 40. In In certain embodiments, the degree of expansion is limited only by the length of the expandable portion 20 in the first state. In some embodiments, a variable expansion feature is provided. A variable expansion feature may enable the clinician to adjust the degree to which an electrode 21 expands. For example, a physician may adjust the degree of expansion to a predetermined diameter before or during a procedure. A variable expansion feature can also be configured to adapt to a procedure or provide feedback to the clinician so that the degree of expansion can be adjusted. For example, the magnitude of an expansion force may be finite and/or nominal after a particular degree of expansion has occurred so that degree of expansion may be limited when the external resistance to expansion is at or near a predetermined threshold, for example example, when a wall or structure is obstructing a complete expansion. Such variable expansion feature can be more adjustable to fit specific applications. For example, an electrode 21 comprising a conductive balloon can be inserted into a lumen and inflated by controllable pressure to substantially conform to the shape of the lumen. Such a complementary shape can increase circumferential contact around the lumen without exerting an invasive force on the tissue. Similarly, in various embodiments, the frame members 52 retain at least partial flexibility when the expandable portion 20 is in the expanded state. For example, frame members 52 may be flexible inwardly toward the axis and/or outwardly from the axis. The elongate member 18 and/or expandable portion 20 may similarly be flexible away from the axis at various angles and directions. In some embodiments, an adaptable feature includes an electrode 21 wherein the length of the expandable portion 20 may be adjustable. For example, in some embodiments, an expandable portion 20 may be withdrawn or received within the sheath 40 so that only the portion of the expandable portion 20 that remains installed is expanded when the expandable portion 20 is selectively transitioned to the expanded state.

[00077] Figure 7 illustrates one embodiment of an expandable portion 20 disposed along an elongate element 18 in accordance with various embodiments. Expandable portion 20 is shown installed from a sheath 40 and is in an expanded state. Frame 50 defines a general perimeter (e.g., a basket) around an axis of expandable portion 20 and includes a first tapered length 24a that diverges about 50° from the axis, a second length 24b that extends substantially parallel to the axis , and a third tapered length 24c that converge about 50 degrees toward the axis. In various embodiments, the basket may be representative of a metallic balloon, metallic cover, or an embodiment similar to Figures 9, 13, or 24, for example, where the degree of expansion is a function of the first and/or third tapered lengths. and the degree to which the tapered lengths diverge from the axis. The elongate member 18 further comprises a distal tip 28 which provides a tapered end to a sharp point. In the contracted state (not shown) the diameter of the expandable portion 20 is reduced by a factor of at least 8 so that the expandable portion 20 can be received within a channel defined within the sheath 40. When installed from the distal end of the sheath 40, expandable portion 20 may be expanded by any disclosed method. As can be seen, the degree of expansion may be a function of the first and/or third tapered lengths 24a,c and the degree to which the tapered lengths 24a,c respectively diverge or converge with respect to the axis. For example, increasing or decreasing the degree of divergence or convergence of the first and/or third tapered lengths 24a,c respectively increases or decreases the degree of expansion while also respectively increasing or decreasing the length of the expandable portion 20. Additionally, increasing or decreasing the lengths of the first and/or third tapered lengths 24a,c respectively increases or decreases the degree of expansion. In embodiments where the first and/or third tapered lengths 24a,c may be extensible, for example, the length of the expandable portion 20 may not increase or decrease during a transition between the expanded state and the contracted state. However, in embodiments, where the first and/or third tapered lengths 24a,c do not extend, an expansion may decrease the length of the expandable portion 20.

[00078] According to various embodiments, the electrodes 21 or expandable portions 20 thereof may be selectively transitioned between a contracted state and one or more expanded states. Figures 8-25 illustrate various non-limiting embodiments of expandable portions 20 of electrodes 21 comprising frames 50 and frame members 52 as well as various non-limiting embodiments of methods of expanding and/or contracting expandable portions 20. Before addressing these embodiments, however, a number of beneficial aspects of these and other modalities will be introduced to assist those skilled in the art in their understanding of the various modalities.

[00079] In some embodiments, transitioning an expandable portion 20 from a contracted state to an expanded state may be driven by an expansion force. Expansion forces may be applied to one or more frame members 52 to effect an expansion. Expansion forces can comprise any known force, such as torque, compression, or tension, for example. In one embodiment, for example, changes in internal pressure trigger transitions with the use of an injectable, such as a solid, liquid, or gas, injected into or released from a defined cavity within a structure 50. The increase in internal pressure can expand the structure 50 at an equilibrium pressure in one or more regions of the structure 50 or can further trigger the expansion by increasing tension around the cavity of the structure 50. Similarly, contraction forces can be applied to one or more frame members 52 to trigger a contraction, such as a contraction between an expanded state and a less expanded state. Contraction forces can comprise any known force, such as torque, compression, and tension, for example, to decrease dimension. For example, in one embodiment, changes in internal pressure trigger transitions with the use of an injectable, such as a solid, liquid, or gas, injected into or released from a defined cavity within a structure 50. The decrease in internal pressure, as a release of an injectable, it may contract the structure 50 to an equilibrium pressure in one or more regions of the structure 50 relieving the tension around the cavity or it can further trigger the contraction releasing additional injectable, thus allowing external pressure to compress the structure. 50 and occupy the cavity.

[00080] In various embodiments, electrical ablation devices 12 may utilize compression, traction, and/or rotation to transition electrodes 21 or expandable portions 20 between contracted and expanded states. In some embodiments, compression of frame members 52 may decrease a length of expandable portion 20 while at the same time increasing a diameter of expandable portion 20. For example, compressed frame members 52 may stretch, bend, or bend. off the shaft to relieve compressive stress. Compression can also trigger a repositioning of frame members 52 within a frame 50 to effect a transition that increases a diameter of an expandable portion 20 without decreasing a length of the expandable portion 20. For example, one or more frame members 52 or portions thereof may be forced off axis or along the elongate member 18 resulting in repositioning of those or other frame members 52 and an increase in one dimension of the expandable portion 20. In some embodiments, the pulling of frame members 52 may increase a length of expandable portion 20 while at the same time decreasing a diameter of expandable portion 20. For example, otherwise curved or outwardly extending frame members 52 may be tensioned to stretch, extend, or straighten inwards towards the axle so as to relieve pulling tension. Traction can also drive the repositioning of frame members 52 within a frame 50 to effect a transition that increases a diameter of the expandable portion 20 without decreasing a length of the expandable portion 20. For example, one or more frame members 52 or portions thereof may be pulled inwardly toward or along the elongate member 18 resulting in repositioning of those or other frame members 52 and a decrease in one dimension of the expandable portion 20. In some embodiments, a rotation of a first coupler configured to couple manipulations that effect relative movements between frame members 52 or portions thereof with respect to a second coupler may increase or decrease a distance between frame members 52 or portions thereof. For example, a decrease in distance may compress one or more interleaved portions or other frame members 52 while an increase in distance may strain one or more interleaved portions or frame members 52.

[00081] In various embodiments, the frame members 52 comprise memory materials. Memory materials may include reflective and/or elastic materials configured to return to a memory orientation or arrangement upon removal of a deformation stress. For example, in some embodiments, frame members 52 are configured to be deformed by a deformation stress above or below an elastic limit and return to a memory shape upon removal of the deformation stress and/or subsequent manipulation, such as a change. in temperature. In certain embodiments, the memory materials include format memory materials having one-way and/or two-way memory effect. Memory materials can also include materials that can be deformable and reformable by manipulation. For example, a first counter-rotation between two portions of a spool may partially unwind the spool while a second counter-rotation, opposite the first, may rewind the spool. Materials having such properties are known in the art and include polymers such as foams, plastics, elastomers, and memory rubbers such as metals and alloys. It should be considered that such materials include superelastics and shape memory materials, such as alloys (eg, NiTi), ceramics, and polymers including gels, foams, and solids. Notably, when frame members 52 comprise memory materials that are weak conductors, conductive materials can be used to establish an electrical path for ablative energy to be transmitted and applied to tissues. For example, conductive coatings, yarns, gloves, and/or fabric contact regions can be used to transmit and apply energy to the fabric. In some embodiments, the elastic limits of frame members 52 may be increased due to the arrangement and/or orientation of frame members 52. For example, the frame members 52 may comprise coil or braid configurations that comprise increased elastic limits due to , for example, distributed stretches.

[00082] In various embodiments, the frame members 52 having a memory shape can be manipulated or otherwise deformed or held by a holding force and upon removal of the holding force, the material returns at least partially to the shape from memory. The frame members 52 having a memory shape can be arranged within the expandable portion 20 in any suitable manner so that the frame members 52 will return to the memory shape following removal of a retaining force or upon manipulation. For example, a frame 50 comprising a conductive coating and including frame members 52 comprising a foam polymer may be configured to expand in at least one dimension upon removal of a holding force and contract in at least one dimension upon application of holding force. In certain embodiments, the holding force is provided by a channel (e.g., an artificial channel defined within an endoscope, trocar, or sheath) in which the expandable portion 20 is received. Other retaining structures can also be used to apply a retaining force. For example, hooks, latches, loops that can be contrived, or other retention mechanisms can be used in certain embodiments to retain frame members 52 and/or prevent frame members 52 from transitioning to one or more memory forms.

[00083] Frame members 52 may individually or collectively have one or more memory forms and/or retained forms. For example, frame members 52 may deform in response to a holding force and return to a memory shape when the holding force is removed. Alternatively, the frame members 52 may comprise a first form of memory and a second form of memory wherein when one or more frame members 52 are in the first form of memory the expandable portion 20 is in an expanded state and wherein when a or more of the frame members 52 are in the second form of memory, the expandable portion 20 is in a collapsed state. In certain embodiments, the memory shape may correspond to the expanded state and thus comprise an increased diameter compared to the retained shape, or it may correspond to the contracted state and thus comprise a decreased diameter compared to the retained shape. Of course, in some embodiments, a holding force may be combined with and or coupled with a second, third, or plurality of additional forces to effect an active transition between the contracted and expanded states.

[00084] Frame members 52 may be configured to deform or stretch to reduce a diameter of expandable portion 20 when frame members 52 are compressed toward the axis or are otherwise retained. In this regard, an electrode 21 may be directed at a tissue treatment region within an artificial channel in a contracted state and be expandable upon placement at or near the tissue treatment site and/or in response to removal of force from the tissue. retention. In one embodiment, a first frame member 52 comprising an incline, such as a spring, foam, or other memory material, is biased off-axis, for example, radially. When the expandable portion 20 is pushed, pulled, or rotated within a channel having a diameter smaller than a diameter of the expandable portion 20 in the expanded state, the channel compresses the first frame member 52 toward the axis, which retains it in a retained form. However, when the expandable portion 20 is pushed, pulled, or rotated from the groove, the first frame member 52 is no longer held by the groove and therefore transitions to the memory shape after positioning and extends off-axis. In another embodiment, a second frame member 52 extends proximally toward the channel when the expandable portion 20 is installed and in the expanded state. The second frame member 52 comprises a proximal lip and a distal compression surface coupled to the outwardly extending portion of the first frame member 52. When the expandable portion 20 is received within the groove, the proximal lip is progressively drawn into the groove. groove, levering the distal compression surface toward the axis, compressing the first frame member 52, and decreasing a diameter of the expandable portion 20.

[00085] Figure 8 illustrates an expandable portion 20 disposed along a distal portion of an elongate member 18. The expandable portion 20 is in the contracted state and is within an artificial channel defined within a sheath 40. The channel has a diameter smaller than a diameter of expandable portion 20 in the expanded state and retains frame members 52 in a retained form. Sheath 40 is operatively connected to a cable 14 (not shown). The handle includes an actuator (not shown), which may be similar to the sliding member 30 illustrated in Figure 1, configured to deploy and withdraw the expandable portion 20 from the distal end of the sheath 40. In some embodiments, the expandable portion 20 may be installed advancing the expandable portion 20 distally of the sheath 40. Accordingly, advancing the expandable portion 20 may comprise proximally withdrawing the sheath 40 or advancing the expandable portion 20 distally with respect to the handle 14. When the expandable portion 20 is received within the sheath 40, a retaining force is applied to the expandable portion 20 by the groove, thereby constraining the expandable portion 20 in the contracted state. However, as illustrated in Figure 9, when the expandable portion 20 is installed from the sheath 40, the frame members 52 are no longer retained by the groove and therefore transition into a memory form. In this embodiment, the memory shape corresponds to the expanded state of the expandable portion 20.

[00086] Still referring to Figure 9, the expandable portion can be transitioned to the contracted state by removing the expandable portion 20 within the channel. When the expandable portion 20 is received within the channel, the channel applies a retaining force to the frame members 52, thereby retaining the frame members 52 in the retained form. An active force such as compression, tension, and/or torque can be used to withdraw and/or deploy the expandable portion 20. For example, the expandable portion 20 can be pushed, pulled, or rotated from or in the groove. Pushing, pulling, or rotating the expandable portion 20 may further be combined with compression applied by the groove to force the frame members 52 to deform toward the axis and transition the expandable portion 20 to the contracted state, as illustrated in Figure 8. In some embodiments, transitioning the expandable portion 20 to a contracted state comprises applying traction to one or more frame members 52. The traction may also be combined with rotation, for example. In some embodiments, proximal traction may force frame members 52 to deform toward the axis and may be combined with distal compression of frame members 52.

[00087] The expandable portion 20 in the expandable state illustrated in Figure 9 includes frame members 52 including a linear portion 25b flanked by a distal tapered portion 25c and a proximal tapered portion 25a. In the memory form, the proximal tapered portion 25a diverges away from the axis at a first angle, and the distal tapered portion 25c converges towards the axis at a second angle. As can be seen, the degree of expansion is a function of the lengths and degree of divergence and convergence of the tapered portions 25a,c. For example, increasing the length of the tapered portions 25a,c increases the diameter of the expandable portion 20. Additionally, the degree of expansion increases as the degree of divergence and convergence approaches 90°. In some embodiments, such expansion in diameter is also accompanied by a reduction in length of the expandable portion 20. While Figures 8 & 9 illustrate a frame 50 comprising four frame members 52 in a basket arrangement, the frames 50 may include any number of frame members 52. For example, in some embodiments, a frame 50 comprises two frame members 52 that extend along the axis. According to the desired application, the diverging and converging angles and tapered lengths they define can be increased to increase the degree of expansion or decreased to decrease the degree of expansion. In certain embodiments, a plurality of 5, 10, 20, or more frame members 52 may extend along the axis and be expandable to a predetermined diameter. In certain embodiments, the frame members 52 may be formed from a sheet or tube of frame material. For example, a frame 50 comprising a sheet or tube may be cut or engraved, for example with a laser, so that one or more frame members 52 or portions thereof may be extensible in the opposite direction of the axis when the expandable portion 20 is in the expanded state. In certain embodiments, a frame 50 comprises an alloy tube body comprising one or more longitudinal frame members 52 laser etched along the body, and when the expandable portion 20 is in the expanded state, the one or more frame members 52 extend off the axis.

[00088] The frame members 52 illustrated in Figures 8 and 9 may comprise a memory material such as superelastics. Memory materials comprising superelastics, such as shape memory materials, can be configured to expand or contract to a memory shape upon release of a holding force or upon manipulation. Frame members 52 that incorporate superelastics may therefore comprise an associated memory shape and an associated retained shape. The retained form may correspond to a martensitic conformation while the memory form may correspond to an austenitic conformation. For example, at austenitic temperatures, the frame members 52 may be retained by a retaining frame, e.g. compressed within the groove, into a martensitic conformation and returned to an austenitic conformation comprising an increased diameter when no longer retained by a retaining frame, for example, when installed from the distal end of sheath 40. Similarly, at martensitic temperatures, frame members 52 may be plastically deformed to a reduced diameter in a martensitic conformation and then returned to an expanded diameter in an austenitic conformation after increasing to the austenitic transition temperature. Similarly, the frame members 52 may be received into the sheath channel 40 in an austenitic conformation and then installed from the distal end of the sheath in the austenitic conformation. When installed, a retaining force comprising a relative decrease in the distance between frame members 52 or portions thereof or an internal extension that extends frame members 52 or portions thereof off-axis can compress or strain the frame members 52 in a martensitic conformation comprising an increased diameter. Upon removal of the holding force at austenitic temperatures, the frame members 52 return to an austenitic conformation comprising a reduced diameter. After removal of the holding force at martensitic temperatures, the frame members 52 can be returned to reduced diameter by the application of a deformation stress or an increase to austenitic temperatures. In some embodiments, frame members 52 have dual sense memory. For example, frame members 52 may comprise at least two forms of memory and be transitional between the at least two forms of memory in response to manipulation. For example, in some embodiments, frame members 52 comprise a low temperature memory form and a high temperature memory form. Frame members 52 can thus be transitioned between the two forms of memory via manipulation which comprises a change in temperature above and below the associated transition temperatures. Of course, as those skilled in the art can deduce from this description, countless variations of one-way and two-way format memory can be used to achieve desired transitions of expandable portions 20 described herein, and hence a further description of all possible variations is unnecessary.

[00089] In some embodiments, the frame members 52 are arranged as a regular array or an irregular array of looped coils, braids, or plies occupying a portion of the expandable portion. In various embodiments, frame members 52 may comprise a material, orientation, and/or arrangement that imparts to frame members 52 a memory shape when loads are within an associated elastic limit. For example, a frame member 52 may comprise a spring (e.g., a bend, compression, torsion, or tension spring) having an associated memory shape and associated elastic limit. The spring can increase or decrease one dimension in response to an application or removal of a load. When the springs are coils or helices wound around the shaft, the frame members 52 can be at least partially unwound when the expandable portion 20 is in the contracted state and the frame members 52 can be rewound when the expandable portion 20 is in in the expanded state. Frame members 52 comprising coils or propellers may also comprise a diameter changed upon the application or removal of a load when, for example, a load stretches a spring longitudinally. In this regard, a physician can, for example, increase a diameter of a frame member 52 by compressing a compression spring or releasing tension applied to a traction spring. Similarly, a physician can, for example, decrease a diameter of a frame member 52 by releasing a compressive load applied to a compression spring or applying tension to a tension spring. In this way, frame members 52 can undergo deformational stretching, such as linear or torsion, into a retained shape and transition to a memory shape upon removal or reversal of a load or force.

[00090] Figure 10 illustrates an expandable portion 20 disposed along a distal portion of an elongate element 18 comprising a spike 28. The expandable portion 20 is illustrated installed from a sheath 40 and in an expanded state. A spiral wound frame member 52 comprising a spring is looped around the shaft and is shown in a memory form comprising an enlarged diameter. It will be understood that the diameter of the expandable portion 20 in Figure 10 can be configured to increase as a function of the gap between the coils. For example, as the gap decreases and the spring length approaches its solid height, the spring diameter increases. The expandable portion 20 in Figure 10 may be transitioned to a contracted state by withdrawing the frame member 52 into a channel defined within the sheath 40 (or a separate channel) that comprises a diameter smaller than the diameter of the expandable portion 20 in the expanded state. . For example, when a proximal pulling force is applied to the expandable portion 20, the expandable portion 20 is received within the channel forcing the frame member 52 to extend longitudinally, thereby reducing the spring diameter and transitioning the frame member. 52 in a retained form. While frame member 52 is retained within the channel, the length of the expandable portion 20 is increased and the diameter of the expandable portion 20 is decreased. When desired, a physician may subsequently transition the expandable portion 20 from the contracted to the expanded state (as illustrated in Figure 9) by installing the expandable portion 20 from the distal end of the sheath 40. Implanting the expandable portion 20 releases the retaining force and allows frame member 52 to transition from retained form to memory form. In some embodiments, the channels may also be equipped with spaced grooves, threads, or tracts, for example, configured to precisely deploy a spring length or number of channel coils.

[00091] In various embodiments, the frame members 52 may be braided to form one or more baskets along a length of the expandable portion 20. In one embodiment, the frame members 52 are braided in a tube-like or cylindrical arrangement. as illustrated in Figure 11. The expandable portion 20 is shown in the process of implantation from a distal end of a sheath 40 concomitant with a transition between a contracted state and an expanded state. Frame members 52 comprise a conductive braid having a memory shape and associated retained shape. Frame members 52 are configured to expand into the memory shape upon removal of a holding force, thereby transitioning the expandable portion 20 from the contracted state to the expanded state. For example, when the expandable portion 20 is in the expanded state, it may be proximally retracted and received within a channel comprising a smaller diameter and transitioned to the contracted state. Tensile tension is applied to the braid when the expandable portion 20 is retracting proximally into the smaller diameter of the channel, forcing the braid to increase in length while decreasing in diameter. Thereafter, the small diameter of the channel maintains compression over the braid and retains the tensile stress within the braid. In the contracted state, the expandable portion 20 is applicable to a tissue treatment region within the channel. When applied to the fabric treatment region, the expandable portion 20 can be installed from the distal end of the sheath 40, thereby decompressing the braid and relieving tensile stress. Consequently, the braid decreases in length and expands about its diameter when the braid is transitioned from retained form to memory form. In this way, removing the holding force relieves the tensile stress within the braid resulting in a reduction in braid length and an increase in a braid diameter. In this way, the expandable portion 20 can transition from the contracted state to the expanded state after the retention force is removed.

[00092] In additional embodiments, the frame members 52 may be arranged in one or more concentric coils (e.g., loops or wraps) of frame members 52 arranged around the axis. An outer belt of the coil can thus be rotatable with respect to an inner belt of the coil so that the expandable portion 20 can be transitioned between the contracted and expanded states by relative rotations between the belts. Such frame members 52 may further comprise an associated memory shape and an associated retained shape so that the relative rotation between the straps comprises a holding force and transitions the expandable portion 20 from an expanded to a contracted state and a release of the holding force transitions the expandable portion 20 from the contracted state to the expanded state. In other embodiments, however, a relative rotation between the straps can transition the expandable portion 20 from the contracted state to the expanded state and a release of a holding force can transition the expandable portion 20 from the expanded state to the contracted state. It should be appreciated that multiple spools comprising multiple belts swiveling relative to one another so that various diameters along the length of the expandable portion 20 can be used to be able to adjust the diameters of the expandable portion 20 to meet various applications.

[00093] In various embodiments, the electrical ablation devices 12 comprise movable portions. The movable portions may comprise frame couplers and/or movable elements including rings, blocks, or collars disposed about or along the elongate member 18. The movable portions may be sliding along a tract, pivoting around threads, or movable over a distance from the elongate element 18, for example. The elongate members 18 and/or expandable portions 20 may further comprise an adjustable distance so that a movable portion does not physically transition along an elongate element 18, but instead moves as a result of a decrease or increase in the relative distance between the movable portion and another movable portion or position along the elongate element 18 or relative to the axis. For example, an elongate member 18 may comprise an adjustable distance where an adjustment to the distance results in a first movable portion moving relative to a second movable portion. In certain embodiments, the distance between movable portions can be adjusted by extending or retracting a folded or nested portion of the adjustable distance, for example. Extension or retraction can be accomplished by, for example, relative rotations, releasing an inclination, and/or applying counter or relative forces between two portions. In one embodiment, an electrical ablation device 12 comprises a movable portion such as a block, ring, coupler, or other element that comprises a contiguous surface. The member may be configured to be movable along an elongate member 18 and be in a position adjacent to a frame member 52. In some embodiments, movement of the member applies compressive stress to frame members 52 or relieves compressive tension. In various embodiments, pulleys or gears may also be used to move the moving portions. For example, the movable portions may move along a track defined along the elongate element 18. The track may include gears configured to move a movable portion or adjust a length of the elongate element 18 between movable portions, for example, by nesting a movable portion. portion of the elongate element 18.

[00094] In various embodiments, frame members 52 may be movable relative to elongate element 18. One or more frame members 52 or portions thereof may be configured to slide along or rotate relative to elongate element 18. For example, a first portion of a frame member 52 may be attached or pivotally attached to the elongate element 18 in a first position and a second portion of the frame member 52 may be attached or pivotally attached to the elongate element 18 in a first position. a second position. Figure 12 illustrates an embodiment of an expandable portion 20 in an expanded state. Expandable portion 20 comprises a plurality of longitudinal frame members 52 disposed along a distal portion of elongate member 18. For the sake of simplicity, only two longitudinal frame members 52 are illustrated. Longitudinal frame members 52 extend along the axis between a proximal movable portion comprising a proximal coupler 54 and a distal coupler 56 adjacent tip 28. Proximal coupler 54 comprises a rotatable portion rotationally movable along elongate member 18 upon threads 60 provided around elongate member 18. Rotation of proximal coupler 54 in a first direction moves proximal coupler 54 proximally and rotation of proximal coupler 54 in a second direction moves proximal coupler 54 distally. Proximal and distal movement of proximal coupler 54 corresponds to relative movement between proximal coupler 54 and distal coupler 56. In one embodiment, when proximal coupler 54 moves distally, the distance between proximal coupler 54 and distal coupler 56 decreases and a compressive stress is applied to the longitudinal frame members 52. The compressive stress causes a marked deformational pull by the bending of the longitudinal frame members 52 off axis, thereby increasing a diameter of the expandable portion 20. Alternatively, when the proximal coupler 54 moves proximally, the distance between the proximal coupler 54 and the distal coupler 56 increases and the compressive strain is relieved. Relief of compressive stress allows the longitudinal frame members 52 to relax inwardly and align longitudinally along the axis, thereby decreasing a diameter of the expandable portion 20. In another embodiment, a proximal movement of the proximal coupler 54 applies a tensile stress to longitudinal frame members 52 resulting in marked deformational traction by inward positioning of longitudinal frame members 52 decreasing a diameter of expandable portion 20. Alternatively, distal movement of proximal coupler 54 relieves tensile stress allowing the longitudinal frame members 52 relax off axis, thereby increasing the diameter of expandable portion 20. In some embodiments, the compressive stress comprises a retaining force and the proximal coupler 54 comprises a retaining frame. Thus, in a memory form, the longitudinal frame members 52 may extend inwardly or curve off-axis, and, in the retained form, the longitudinal frame members 52 may be compressed to bend off-axis or tensioned. to straighten and radially align inward toward the axis. In some embodiments, frame members 52 do not rotate in correspondence with rotation of a proximal or distal coupler 56. For example, the couplers may comprise contiguous surfaces configured to compress a first portion of a frame member 52 against or relative to a second portion of a frame member 52. In certain embodiments, the couplers may comprise a track whereby a first portion of frame member 52 can maintain axial positioning with respect to a second portion of the frame member 52. similarly, the couplers may comprise a sleeve whereby a first portion of a frame member 52 is coupled. The sleeve may be rotatable about an inner portion of the coupler by bearings so that the first portion of frame member 52 can maintain axial positioning that corresponds to movements of the inner portion of the coupler.

[00095] It should be noted that proximal and distal guidance is provided to aid in understanding the systems, devices, and methods disclosed herein. In certain embodiments, the guidelines and/or provisions may be reversed so that the objective of transitioning an expandable portion remains the same. For example, distal coupler 56 may be rotationally movable via threads, for example, provided proximate to distal coupler 56. Such orientational variations do not deviate from this description. Indeed, in one embodiment, the proximal coupler 54 and the distal coupler 56 are rotatable around the threads provided about the surface of the elongate member 18. Similarly, in another embodiment, the distal coupler 56 is clickably movable along the surface of the elongate element 18. along the elongate member 18. In additional embodiments, a series of frame arrangements 50 and/or expandable portions 20 may be disposed along the distal portion of the elongate member 18. Such a series of frame arrangements 50 and/or expandable portions 20 may be configured for a desired application and provide customizable ablation zones within a biological lumen or treatment site.

[00096] Figure 13 illustrates an embodiment of an expandable portion 20 comprising a four-membered basket. Frame members 52 are coupled to a proximal coupler 54 and a distal coupler 56. The proximal coupler 54 is movable relative to the distal coupler 56 such that a decrease in the distance between the couplers 54, 56 increases a diameter of the expandable portion 20 , as shown in Figure 14, and an increase in the distance between the couplers 54, 56 decreases the diameter of the expandable portion 20, as shown in Figure 13. As shown in Figure 14, in the expanded state, the frame members 52 have a proximal tapered portion 26a and a distal tapered portion 26b defining an interior angle of about 80°. In some embodiments, the degree of expansion is a function of the lengths 26a,b and the angle defined therebetween. For example, increasing a length 26a,b can increase the degree of expansion and decreasing the angle defined between the lengths 26a,b can increase the degree of expansion. In some embodiments, a portion of the elongate element 18 is translatable through the proximal coupler 54 and fixed with respect to the distal coupler 56 so that retracting the elongate element 18 relative to the proximal coupler 54 decreases the distance between the proximal coupler 54 and the distal coupler 56 and advancing the elongate element 18 relative to the proximal coupler 54 increases the distance between the proximal coupler 54 and the distal coupler 56. Consequently, when the elongate element 18 is retracted proximally, the distal coupler 56 moves proximally and frame 52 compress and bend outward into a retained shape corresponding to an expanded state of the expandable portion 20. Similarly, the frame members 52 may comprise a memory shape corresponding to an expanded state of the expandable portion 20 so that when elongate member 18 is retracted proximally, distal coupler 56 moves proximally, and frame members 52 tense. and straighten inwardly into a retained shape corresponding to a contracted state of the expandable portion 20. Compression of frame members 52, as illustrated in Figure 14, can result in radial bending of frame members 52 off axis, increasing a diameter of expandable portion 20. Depending on the desired application, numerous configurations of a plurality of frame members 52 disposed along an axis may be configured to flex, bend, deform, or otherwise pull in response to stress. For example, frame members 52 may be configured to flex, bend, deform, or otherwise pull into two or more positions, thereby forming a basket similar to that shown in Figure 9. In some embodiments, 5, 6, 8, 15, or more frame members 52 may be provided so long as they flex, bend, deform, or otherwise pull along a plurality of positions and, for example, take a spherical shape in the expanded state.

[00097] Figure 15 illustrates yet another embodiment of an expandable portion 20. In this embodiment, relative movements between the frame members 52 expand the umbrella-like expandable portion 20. In particular, one or more frame members 52 comprising extenders 53 are provided. First ends 53a of stents 53 are pivotally coupled to a proximal coupler 54 positionable along a length of elongate member 18. Second ends 53b of stents 53 are pivotally coupled to one or more additional frame members comprising ribs 51. The ribs 51 may comprise a flexible material (e.g., an elastic band, a series of hinged frame members, or a portion of a flexible cover) or, in some embodiments, a rigid material and may be fixedly coupled to the elongate member 18 in a distal coupler 56 adjacent the distal tip 28 so that the stent extension 53 extends portions of the ribs 51 off the axis. The stents 53 are preferably rigid enough to extend the ribs 51 by, for example, bending, bending, or swinging the ribs 51 off-axis. In the illustrated embodiment, a transition between the contracted state and an expanded state comprises a relative movement between the proximal 54 and distal 56 couplers. For example, a transition from the contracted state to an expanded state comprises decreasing the distance between the couplers 54, 56. A relative movement between the couplers 54, 56 can be achieved in any suitable manner. For example, in one embodiment, a physician may distally reposition proximal coupler 54 by proximally pulling a nested portion of elongate member 18 comprising distal coupler 56 using an actuator provided on the handle (not shown). Figure 16 illustrates an embodiment of the expandable portion 20 shown in Figure 15 in an expanded state. As can be seen, the stents 53 brace and extend the ribs 51 off the axis in response to relative movement between the proximal 54 and distal 56 couplers. In this embodiment, the proximal coupler 54 includes a rotatable portion rotatable by threads 60 provided about. from an adjacent surface of the elongate member 18. The stents 53 are extensible by distally rotating the proximal coupler 54 and retractable by proximally rotating the proximal coupler 54. In various embodiments, the proximal coupler 54 is repositionable by sliding the coupler 52 proximally or distally along the member. 18. In additional embodiments, the second or third stents may be associated with first stents 53. For example, the second stents may comprise a first end pivotally coupled to a central portion of a first stent and a second end pivotally coupled to a second stent. pivoting to an additional structure member, such as a nervu ra 51. Third party extenders can be similarly configured. The second and third extenders may provide additional structure and or support for expandable portions 20 or increase expansion. In other embodiments, an extender 53 may be a wedge having an engagement surface configured to engage and brace a rib 51. For example, as the distance between the wedge and distal coupler 56 decreases, the wedge progressively moves along from the underside of rib 51, swinging rib 51 off axis, and expanding a diameter of expandable portion 20.

[00098] Figure 18 illustrates a further embodiment of an expandable portion 20 comprising two pivotally coupled frame members 52a,b. Expandable portion 20 is illustrated in a slightly expanded state. Frame members 52a,b are pivotally coupled about a joint 62 (e.g., a hinge, pin, or flexible portion) at adjacent ends. Each frame member 52a,b is pivotally coupled to the elongate member 18 by about additional joints 62 on respective proximal 54 and distal 56 couplers. The proximal 54 and distal 56 couplers are relatively movable relative to each other. In this embodiment, transitioning the expandable portion 20 from the contracted state to the expanded state comprises moving the proximal 54 and distal 56 couplers relative to each other and comprises nesting an interleaved portion of the elongate element 18. For example, nesting the distal portion within the proximal portion of the elongate element 18. decreases the distance between the proximal 54 and distal 56 couplers, resulting in an outward rotation of the adjacent ends of the frame members 52a,b, increasing a diameter of the expandable portion 20, and thus expanding the expandable portion 20. Otherwise, misalignment the distal portion of the proximal portion increases the distance between the proximal 54 and distal 56 couplers, resulting in an inward rotation of the adjacent ends of the frame members 52a,b, decreasing the diameter of the expandable portion 20, and thus contracting the expandable portion 20 For the sake of simplicity, Figure 18 only includes two coupled frame members 52a,b; however, additional frame members may similarly be coupled to frame members 52a,b. For example, a third frame member may be coupled between the two frame members 52a,b shown in Figure 18 so that relative movement between the proximal 54 and distal 56 couplers extends the third frame member off the relatively parallel axis. with the axis. Also for the sake of simplicity, Figure 18 only includes two sets of coupled frame members 52a,b; in additional embodiments, three or more sets of coupled frame members 52a,b are provided around the circumference of the elongate member 18 to further increase the diameter of the expandable portion 20 in the expanded state.

[00099] In certain embodiments, the frame members 52 may comprise a coil operatively coupled to the elongate element 18 in a first position. In such an embodiment, the relative counter-rotation between the first position and a second position at least partially unwinds the coil and corresponds to an increase in a diameter of the expandable portion 20. For example, when the frame member 52 is a coil or helix to the right a clockwise rotation from a proximal position relative to a distal position transitions the expandable portion 20 between a contracted state and an expanded state while a counterclockwise rotation of the proximal position relative to the distal position transitions the portion expandable 20 from an expanded state to a contracted state. Similarly, when frame member 52 is a coil or left helix, a clockwise rotation from the distal position relative to the proximal position transitions the expandable portion 20 from a contracted state to an expanded state while a counterclockwise rotation clockwise from the distal position relative to the proximal position transitions the expandable portion 20 from an expanded state to a more contracted state. In a similar embodiment, the longitudinal distance between the proximal and distal positions is also adjustable. For example, the proximal position can be slid towards the distal position, thus reducing the distance between the two. In one embodiment, one or both of the positions are threadably rotatable about the elongate member 18 so that rotation of the positions increases or decreases the distance between the proximal and distal positions. In other embodiments, one or both of the positions are clickable or slidably positionable along the elongate element 18. It should be appreciated that a spool can be swiveled in multiple positions so that various diameters along the length of the expandable portion 20 can be adjustable to meet various applications.

[000100] Figure 18 illustrates one embodiment of an expandable portion 20 in the contracted state comprising a spiral wound frame member 52. The coil is coupled to the elongate member 18 in a distal coupler 56 adjacent a distal tip 28 so that a transition of the expandable portion 20 from the contracted state to an expanded state comprises a counter-rotation between the distal coupler 56 and a proximal position 58 of the frame member 52, as illustrated in Figure 19. It should be appreciated that the coil may be proximally coupled or fixed with respect to the sheath 40 or otherwise proximally independent of a rotation of the distal coupler 56. Figure 19 illustrates an embodiment of the expandable portion 20 shown in Figure 18 in the expanded state following multiple clockwise rotations of the distal coupler. 56 with respect to the proximal portion 58 of the coil. In accordance with this embodiment, counterclockwise rotation of the distal coupler 56 relative to the proximal portion 58 of the coil transitions the expandable portion 20 from an expanded state to a less contracted state. Figure 20 illustrates another embodiment of the expandable portion 20 shown in Figures 18 and 19 and includes a method of further increasing the degree of expansion of the expandable portion 20 by decreasing its length. For example, a physician may withdraw a portion of the elongate member 18 within the sheath 40 while maintaining the length of frame member 52 installed from its distal end. In this regard, the expandable dimension can be further customized to fit any of a number of desired applications.

[000101] Figure 21 illustrates an expandable portion 20 comprising a frame member 52 oriented in a tube-like braid that extends along a distal portion of an elongate member 18. Expandable portion 20 is illustrated in a partially installed and is in a contracted state. The proximal end of the braid is coupled to a proximal coupler 54 (shown in cutout). The distal end of the braid is coupled to a distal coupler 56 adjacent a distal tip 28. In this embodiment, relative movement between the proximal coupler 54 and the distal coupler 56 transitions the expandable portion 20 between a contracted state and an expanded state. Notably, in some embodiments, a sheath 40 may be provided as long as it can, in certain instances, at least partially be used as a proximal coupler 54. For example, as illustrated in Figure 22, when distal coupler 56 moves proximally relative to the proximal coupler 54, the braid is compressed. The braid orientation of frame member 52 also enables loosening of the braid so that the distance between individual overlaps of frame members 52 within the braid increases in response to compressive stress. Because the length of installed braid does not decrease to the point of relative movement between the proximal coupler 54 and the distal coupler 56, a dimension, or in this instance, a diameter, of the expandable portion 20 increases. Alternatively, when relative movement between the proximal coupler 54 and the distal coupler 56 results in an increase in the distance between the respective couplers 54, 56, tension on the frame members 52 decompresses the braid, decreasing a diameter of the expandable portion 20 to a less expanded state. In some embodiments, a complete transition from an expanded state to a contracted state comprises relative movement between the proximal coupler 54 and the distal coupler 56 increasing the distance between the two couplers such that the tensile stress applied to the braid is sufficient to contract. the braid to a predetermined diameter.

[000102] Figure 23 illustrates another embodiment of the expandable portions 20 illustrated in Figures 21 and 22 that includes an additional feature for customizing the degree of expansion. In this embodiment, a physician can selectively control or choose the degree to which the expandable portion 20 expands by adjusting the distance between the proximal coupler 54 and the distal coupler 54. As can be seen, a decrease in distance between the coupler 54, 56 increases a diameter of the expandable portion 20 while an increase in the distance between the couplers 54, 56 decreases the diameter. In this regard, a physician can beneficially control the diameter of the expandable portion 20. Furthermore, when a sheath 40 is provided which can be at least partially used as a proximal coupler 54, a physician can compensate for a decrease in length of the expandable portion. installed 20 by installing an additional expandable portion 20 (such as frame members 52) which can also be compressed to increase the diameter of the expandable portion 20.

[000103] As previously described, one or a multiple of methods can be used to effect relative movement between a first movable portion that comprises a proximal portion of frame members 50, such as a proximal coupler, and a second movable portion that comprises a distal portion of frame members 52, as a distal coupler. For example, in some modalities, a physician may engage an interface to signal actuation or relative movement between the first and second portions. The actuation signals can trigger transitions effected by mechanical and/or electrical elements. In certain embodiments, an actuator comprises a manipulator configured to manually extend or retract portions of frame members 52 and/or portions of elongate member 18. A signal may result in a coupler rotating around a threaded rail, as in Figure 12, for example, or a sliding of the first movable portion relative to the second movable portion, as in Figure 14, for example. The elongate element 18 can additionally be equipped with longitudinal tracks or rails in which the first and/or second movable portions can transition. In some embodiments, an elongated element interleaved span 18 between the first and second movable portions may decrease in length by nesting or telescopically folding into an adjacent span, as, for example, in Figure 17. Such a decrease in length of an interleaved element span elongate 18 may be assisted by an incline configured to releasably extend or retract the intervening span. In certain embodiments, frame members 52 and/or elongate member 18 may be equipped with gears configured to move portions thereof relative to each other.

[000104] Figure 24 illustrates an expandable portion 20 in an expanded state in accordance with various embodiments. Expandable portion 20 comprises a plurality of frame member 52 comprising thermoresponsive shaped memory material defining a basket. The frame members 52 extend along the axis and each comprise a linear portion 27b flanked by a distal tapered portion 27c and proximal tapered portion 27a. As shown, the proximal tapered portion 27a of each frame member 52 diverges away from the axis at a first angle, and the distal tapered portion 27c of each frame member 52 converges towards the axis at a second angle. As can be seen, the degree of expansion is a function of the lengths of the tapered portions 27a,c and their degree of divergence in the opposite direction and convergence towards the axis. For example, increasing the length of the tapered portions 27a,c increases the diameter of the expandable portion 20. Additionally, the degree of expansion increases as the degree of divergence and convergence approaches 90°. In some embodiments, such expansion in diameter is also accompanied by a reduction in length of the expandable portion 20. When the expandable portion 20 is in the contracted state, as illustrated in Figure 25, proximal tapered portions 27a, linear portions 27b, and distal tapered portions 27c extend relatively linearly along the axis so that the expandable portion 20 can be received by a channel defined within the sheath 40.

[000105] In the embodiment illustrated in Figures 24 and 25, the frame members 52 exhibit dual sense memory. That is, the frame members 52 comprise at least two forms of memory and are transitional between the at least two forms of memory in response to changes in temperature. At temperatures at or below a low transition temperature, the frame members 52 are in a low temperature form. At temperatures at or above a high transition temperature, the frame members 52 are in a high temperature form. Depending on the desired application, the low temperature shape can correspond to the expanded state or the contracted state and the temperature shape can correspond to the expanded state or the contracted state. A clinician can signal a transition comprising a temperature change via an actuator located on the handle (not shown). Actuation may result in energy transmission, such as vibrations, to frame members 52 sufficient to raise the temperature of frame members 52 and effect a transition to high temperature form. Acting may also comprise positioning in a biological environment, in some modalities. For example, a transition temperature can be set at or below a biological temperature so that when frame members 52 are exposed to biological temperatures, the expandable portion 20 undergoes a transition.

[000106] In some embodiments, a sheath 40 is not provided and an electrode 21 may be applied to a target region within another delivery device. In some of such embodiments, the electrode 21 can be applied to the target region with nothing, i.e. not inside an artificial channel. In these and other embodiments, electrode 21 can be applied to a target region by advancing elongate element 18 through a biological hole or lumen. When applied to the target region, electrode 21 can be expanded in response to an actuation signal. The electrical ablation device 12 illustrated in Figure 26 is configured for use and application to a target region within an artificial or bare delivery channel. Device 12 includes a cable 14 through which an elongate conductive element 18 extends. Near the proximal end of the cable 14, the elongate element 18 comprises a connector 19 for connecting the elongate element 18 to the power supply (not shown). The elongate member 18 extends distally from the distal end of the handle 14 and includes an electrode 21 disposed along a distal portion of its length and a distal tip 28. The electrode 21 comprises an expandable portion 20 comprising a plurality of frame members. 52 arranged in a basket similar to the embodiment shown in Figure 24. Cable 14 comprises an actuator 31 configured to transition expandable portion 20 between contracted and expanded states by any suitable method.

[000107] In various embodiments, the elongate element 18 may be flexible along all or a portion of its length. Such flexible portions may be flexible, deformable, or elastic, for example. The flexible portions may also be conditionally flexible or conditionally rigid. In some embodiments, the elongate element 18 comprises flexible portions that can be mechanically flexible so that the portions of the elongate element 18 are pivotable in response to a signal or otherwise manipulable. In one embodiment, the elongate element 18 comprises a maneuverable portion configured to maneuver within a biological lumen such as a vascular, duct, cavity, orifice, or tract area, for example, and apply an electrode 21 to a target site. . In one embodiment, a cardiac catheter platform comprises one or more electrodes 21 disposed along the distal portion of an elongated flexible and/or maneuverable element 18 configured to deliver the one or more electrodes 21 into a chamber, vessel, or surface of the heart. for endocardially ablating spots to treat atrial fibrillation, for example. The one or more electrodes 21 may be selectively expandable between contracted and expanded states. In some embodiments, multiple electrodes 21 are disposed along the distal portion of elongate element 18 and spaced to apply energy to cardiac tissue within a tightly controlled electrical field. In some such embodiments, the distance between electrodes 21 along the distal portion of elongate member 18 may be adjustable to conform to a particular procedure.

[000108] Referring to Figure 27, a cardiac catheter platform according to various embodiments is illustrated. The platform comprises a catheter assembly comprising an electrode 21 disposed along a distal portion of an elongate element 18. The platform further comprises a cable 14 configured to maneuver the elongate element 18 and electrode 21 under imaging in the heart to make endocardially ablation of spots or spots as a treatment for atrial fibrillation. In the illustrated embodiment, the elongate element 18 is equipped with a long insulated tip 28 located at the distal end of the elongate element 18. The tip 28 may be configured to beneficially enhance a clinician's ability to thread, direct, or navigate the element. elongate 18 and electrode 21 to a tissue treatment region. In various embodiments, a cardiac catheter platform may comprise an expandable portion 20 which comprises a comparatively increased length relative to certain other embodiments. An increased length may be advantageous in certain treatment applications by allowing a clinician to more easily connect ablative points along a desired lesion line. In some embodiments, an expandable portion 20 comprising an adjustable length as described above may be provided to customize the expandable portion 20 to flexibly fit particular surgical applications. In some embodiments, the length may be conveniently adjusted at or near the tissue treatment site. Such a feature can beneficially shorten treatment time by enabling a physician to adjust the expanded length of lead 21 to adaptively connect ablative points during a procedure without a need to completely remove the catheter. Referring again to Figure 27, a system comprising the illustrated cardiac catheter may additionally comprise a second electrode 22 (not shown) configured to couple with a power source (not shown). The second electrode 22 may be a return pad, needle, gripper, second probe, or second electrode disposed along the distal portion of the elongate element 18.

[000109] Figure 28A includes a photograph of an ablation zone following ablative treatment according to various modalities. Using the intravascular approaches described herein, one electrode 21 was placed in a porcine liver duct and a second electrode 22 comprising a return was placed over the skin. As can be seen, following the ablative treatment, an ablation zone 80 surrounded the vessel. No injuries or burns were observed in the tissue around the return site. Figure 28B includes a photograph of an ablation zone 80 following ablative treatment in accordance with various modalities. Using the intravascular approaches described here, one electrode 21 was placed in a porcine liver vessel and a second needle electrode 22 was placed in the liver parenchyma. As can be seen, following the ablative treatment, an ablation zone 80 surrounded the vessel. Figure 29 includes a photograph of an endocardial ablation zone 80 following ablative treatment in accordance with various modalities. Using the intravascular approaches described here, an electrode 21 was placed in contact with porcine heart tissues. Following ablative treatment, an ablation zone 80 comprising a line of injury along cardiac tissue was observed.

[000110] In various embodiments, electrical ablation devices 12 include accessory features such as optics, applicators, and sensors. For example, transducers or sensors may be located on cable 14, or tip 28, or other suitable location to detect, for example, the force required to expand an electrode 21. This feedback can be useful in determining whether electrodes 21 have been properly positioned within a biological lumen at or near a tissue treatment site. Manual actuation of an expandable portion 20 can similarly provide feedback to a physician as to the force required to fully expand the expandable portion 20. In this regard, the physician may decide that full expansion of the expandable portion 20 is unnecessary or may otherwise result in unnecessary trauma and adjust the degree of expansion accordingly. In certain embodiments, feedback is provided to the physician to physically detect when an electrode 21 is placed on or near a tissue treatment site. In some embodiments, feedback provided by transducers or sensors may be processed and presented by circuits located internally or externally to the power source 11. Sensor readings may be used, for example, to determine whether an electrode 21 was properly located at or close to a tissue treatment site thus ensuring that an adequate margin of error has been achieved in the location of electrode 21. Sensor readings can also be used, for example, to determine if pulse parameters need to be adjusted to achieve a desired result, such as, for example, reducing the intensity of muscle contractions in the patient.

[000111] In one embodiment, an electrical ablation device 12 includes an accessory feature comprising an electrolyte applicator. An electrolyte applicator can be configured to apply or deliver an exogenous electrolyte at or near a tissue treatment site. An electrolyte applicator may include an application portion and a reservoir portion. In some cases, the application portion may comprise the reservoir portion. The reservoir portion may be configured to contain electrolyte for application. The application portion may be configured to deliver electrolyte at or near the tissue treatment site. In some embodiments, the application portion comprises a channel adjacent to or within the elongate member 18 or sheath 40. In one embodiment, the application portion comprises a spike 28. A physician may actuate an actuator located on the handle 14, for example, to apply electrolyte from the application portion. In certain embodiments, the application portion may be capable of independent positioning of the electrode 21 of an artificial lumen or channel. In some embodiments, the application portion, reservoir portion, or electrolyte applicator may be separate from the electrical ablation system 10. In various embodiments, the application portion of an electrolyte applicator may apply an aqueous solution of electrolyte to the area. of treatment before or during a treatment to increase conductivity. In other embodiments, however, no solution can be added or a separate accessory feature or the same accessory feature can be configured to apply suction to a treatment area to, for example, remove fluids before or during a treatment.

[000112] In certain embodiments, at least one of a temperature sensor and pressure sensor may be located on or adjacent to the electrical ablation system 10. The temperature sensor and/or pressure sensor may be located within the cable 14, protective sleeve 38, sheath 40, elongate element 18, at the distal end of elongate element 18, such as tip 28, or within one or more electrodes 21. In certain embodiments, the temperature sensor and/or pressure sensor may be separate of the electrical ablation system 10. The temperature sensor and pressure sensor can provide feedback to the operator, surgeon, or physician to apply an electrical field pulse to unwanted tissue. Pressure and/or temperature information can be useful in determining whether unwanted tissue can be treated with reduced thermal effects or no harmful thermal effects on surrounding healthy tissue. In accordance with certain embodiments, the temperature sensor can measure the temperature of the tissue treatment region, unwanted tissue, or the area surrounding one or more electrodes before, during, and/or after treatment as well as before and/or after the treatments. first and/or second sequences of electrical pulses to be applied to the tissue. In accordance with certain embodiments, the pressure sensor may measure the pressure of the tissue treatment region, the space between the electrodes, and/or the area surrounding one or more electrodes before, during, and/or after treatment, such as before and/or after the first and/or second sequences of electrical pulses are applied to the tissue.

[000113] The electrical ablation system 10 can be used to excise unwanted tissue in delicate areas or close to critical structures and be installed through a biological lumen, such as vascular, duct, or tract areas. The electrical ablation system 10 can be configured to treat a number of lesions and osteopathologies comprising metastatic lesions, tumors, fractures, infected sites, and inflamed sites in a tissue treatment region with the use of electrical energy. Electrical ablation devices 12 may be configured to be positioned within a patient's natural bodily orifice, e.g., the mouth, anus, and vagina, and/or advanced through the internal body lumen or cavities, e.g., the esophagus. , stomach, intestines, colon, cervix, and urethra, to reach the tissue treatment region. For example, an elongate member 18 can be configured to be positioned and passed through a small incision or keyhole-shaped hole formed through the patient's skin or abdominal wall using a trocar to reach the tissue treatment region. The tissue treatment region can be located in the brain, lung, breast, liver, gallbladder, pancreas, prostate gland, various lumens of internal bodies defined by the esophagus, stomach, intestine, colon, arteries, veins, anus, vagina, cervix, fallopian tubes, and the patient's peritoneal cavity. The electrical ablation system 10 can be used in conjunction with endoscopic, laparoscopic, thoracoscopic, open surgery procedures via small incisions or keyhole holes, percutaneous techniques, transcutaneous techniques, and/or non-invasive external techniques, and any combinations of the same.

[000114] In one embodiment, the electrical ablation device 12 may be used in conjunction with an artificial channel (e.g., a flexible endoscope, as well as a rigid endoscope, laparoscope, or thoracoscope, such as the GIF-100 model available with the Olympus Corporation). In one embodiment, the endoscope may be introduced to the tissue treatment region transanally through the colon, transorally through the esophagus and stomach, transvaginally through the cervix, transcutaneously, or via an external incision or hole in keyhole shape formed in the abdomen in conjunction with a trocar. Electrode 21 can thus be applied to a tissue treatment region via insertion and guided in or adjacent to the tissue treatment region using the endoscope. Such an application can also be achieved with the use of various other artificial channels. The endoscope or other artificial channel may define one or more channels to receive additional devices such as a light source and viewport. Images within the viewport's field of view may be received by an optical device, such as, for example, a camera comprising a charge-coupled device (CCD, or charge-coupled device) usually located within the endoscope, and transmitted to a display monitor (not shown) outside the patient. In other embodiments, the endoscope is not used, and the electrical ablation device 12 comprises a light source and/or a viewing port, for example. Still additional modalities use other techniques to determine the appropriate placement of instruments, such as ultrasound or a computed tomography (CT) scan.

[000115] According to one embodiment, the methods of electrically ablating tissue include applying a first electrode 21 to a tissue treatment region. The first electrode 21 may be configured to mate with the power source and a tissue treatment region located within or near a lumen. In one embodiment, the first electrode 21 is applied or directed into a lumen at or near a tissue treatment region through a hollow hole, such as an artificial channel. The first electrode 21 can then be installed at or near a tissue treatment site. When installed, an expandable portion 20 of the first electrode 21 can be expanded by at least one dimension (e.g., diameter or length) and then brought into contact with the lumen wall. A second electrode 22 may be coupled to the first electrode 21 and the patient so that the second electrode 22 is in conductive communication with the first electrode 21 across the patient and represents a difference in electrical potential with respect to the first electrode 21. For example, in some embodiments, the second electrode 22 may be a ground or return pad, a needle electrode, or medical gripper in contact or conductive communication with the patient. In various embodiments, the second electrode 22 may be a separately placed electrode, such as a conductive material, return pad, needle, or gripper, for example, it may be located near or adjacent to the tissue, surface, or lumen. When applied to a tissue treatment region, the first electrode 21 can be driven (e.g., installed, expanded, and energized) to excise unwanted tissue.

[000116] In some embodiments, expanding an expandable portion 20 of a first electrode 21 comprises transitioning the expandable portion 20 from a contracted state to an expanded state. Transitioning an electrode 21 from a contracted state to an expanded state may comprise increasing at least one dimension of the electrode 21. In certain embodiments, when the expandable portion 20 transitions from the contracted state to the expanded state, a diameter of the expandable portion 20 proportionally decreases in length. . In other embodiments, however, the diameter of the expandable portion 20 does not expand proportionally to a decrease in length.

[000117] In some embodiments, the first electrode 21 may be alternatively or selectively transitionable between a contracted state and an expanded state. In certain embodiments, a transition from a contracted state to an expanded state comprises a relative movement between two portions of a structure or structure members 52. The relative movement may be rotational or longitudinal. For example, a decrease in the distance between two portions of a frame 50 or frame members 52 can transition an expandable portion 20 from a contracted state to an expanded state. Relative movement may result in one or more frame members 52 extending off axis. Outward extension may be the result of bending one or more frame members 52. Frame members 52 that extend off-axis may similarly brace, extend, or otherwise reposition other frame members. frame 52 off axis. Various memory materials and orientations of frame members 52 may be used to assist in transitioning an expandable portion 20 between contracted and expanded states. For example, frame members 52 may be arranged as springs, coils, braids, multi-member baskets, umbrellas, and injectable cavities and may comprise rigid, jointed, or memory materials, including permanent deformation memory superelastics of Format. For example, frame members 52 can comprise metals, alloys, rubbers, plastics, polymers, and various conductive materials.

[000118] In various embodiments, expanding an electrode comprises expanding a diameter or radius or expandable portion many times that of the electrode in a contracted state. Depending on the desired application, the electrodes can expand 2, 5, 10, 20, 40 or more times in diameter or radius to expand to a diameter that conforms to a diameter of a tissue treatment region comprising a biological lumen, such as, for example, a larynx. In various embodiments, the diameter of the first electrode may be different from the diameter of the second electrode. Similarly, in some embodiments, the first electrode may have a different length than the second electrode. Again, depending on the desired application, such variations are contemplated and are considered within this description. As is to be understood, when multiple electrodes are disposed along the distal portion of an elongate element, various spacings between the electrodes may also be desirable. In some such embodiments, the distance from the first electrode to the second electrode can be adjusted from 0.5 cm to 3 cm, such as 1 cm, 1.5 cm, 2.0 cm, and 3 cm. However, in other applications it may be desirable to greatly increase the distance between the first and second electrodes to, for example, customize the size of the electric field for a particular application.

[000119] Electrodes 21 may be introduced, applied, installed, or expanded according to any of the above methods and then placed in contact with a lumen wall. Contact with a wall of the lumen is preferably at least partially circumferential. The electrical current can then be applied to various pulse power outputs, such as single-phase square waves, two-phase square waves, RF modulated high voltage, or nanosecond-duration pulses, for example. The applied current and waveform can be customized for the desired application and clinical objective to provide various tissue effects such as cell lysis, apoptosis, or irreversible electroporation.

[000120] Figure 30 is a representative use of an electrical ablation system and device in accordance with various embodiments. An elongate member 18 applies the expandable portion 20 to a region of tissue comprising a lumen 82 (e.g., a hepatic vein) using the methods disclosed herein. An alternate application placement of the elongate element 18' is additionally indicated by the dashed outline. The expandable portion 20 is then installed from the distal end of the sheath 40 to the target site (eg, a tumor surrounding the hepatic vein). When installed, the expandable portion 20 is expanded, for example, transitioned from a contracted state to an expanded state. In Figure 30, saline is introduced into the lumen to increase electrical conductivity before treatment (not shown). The expandable portion 20 is then contacted with a wall of the lumen and the ablative treatment is applied. Figure 30 illustrates an ablation zone 80 of cells that were ablated following such treatment. As can be seen in this representation, in some embodiments, the dimensions of the expandable portion 20 in the lumen can determine the size of the zone.

[000121] While various embodiments of the devices have been described herein in connection with certain embodiments presented, many modifications and variations of these embodiments can be implemented. For example, different types of end actuators such as tips, electrodes, and elongated elements can be used. Also, where materials are disclosed for certain components, other materials may be used. The aforementioned description and the following claims are intended to encompass all such modifications and variations.

[000122] Any patent, publication or other descriptive material, in whole or in part, which is said to be incorporated by reference into the present invention is incorporated into the present invention only to the extent that the incorporated materials do not come into conflict with existing definitions, statements or other descriptive material presented in this description. Accordingly, and to the extent necessary, the description as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, which is incorporated by reference in the present invention, but which conflicts with existing definitions, statements, or other descriptive materials set forth herein, will be incorporated herein only to the extent that no conflict will appear between the embedded material and the existing description material.

Claims (13)

1. Electrical ablation device (12), comprising: an elongate element (18); a first electrode (21) disposed along the elongate element (18) and extending along an axis, the first electrode (21) having a proximal end configured to engage a power source (11) and a surface shaped to couple to a tissue treatment region and apply an ablative energy; and a first expandable portion (20) having a proximal end and a distal end and extending along the axis, the first expandable portion (20) defining a first perimeter of the first electrode (21) and having an associated first diameter with respect to the shaft, wherein the first expandable portion (20) comprises a first frame (50) comprising at least one frame member (52), wherein the frame member (52) comprises a helix extending to the along the first expandable portion (20), wherein a distal end of the frame member (52) is configured to supply electrical current, wherein the first expandable frame (50) selectively transitions the first expandable portion (20) from a contracted state to an expanded state, and the first structure (50) is selectively contractible to transition the first expandable portion (20) from the expanded state to the collapsed state, wherein, when the first structure (50) is exp Then, the first diameter is expanded and the first expandable portion (20) is transitioned from the contracted state to the expanded state, wherein when the first structure (50) is contracted, the first diameter is contracted and the first expandable portion (20) is transitioned from the expanded to the contracted state, characterized in that a relative rotation between a proximal portion and a distal portion of the frame member (52) transitions the first expandable portion (20) between the contracted state and the expanded state , and wherein the relative rotation between the proximal portion and the distal portion of the frame member (52) comprises a counter-rotation of the distal portion of the frame member (52) with respect to the proximal portion of the frame member (52). 2. Electrical ablation device (12) according to claim 1, characterized in that the first electrode (21) comprises a first flexible portion (16), and wherein at least a portion of the first expandable portion (20) ) comprises at least a portion of the first flexible portion (16). 3. Electrical ablation device (12) according to claim 1, characterized in that the first structure (50) is expandable to expand the first diameter to circumferentially contact a biological lumen at two or more locations in around the circumference of the biological lumen. 4. An electrical ablation device (12) according to claim 1, characterized in that the frame member (52) has an associated memory shape and an associated retained shape, and wherein the frame member (52) ) is transitionable between the memory form and the retained form to expand and contract the first structure (50). 5. Electrical ablation device (12), according to claim 4, characterized in that it further comprises a retaining structure configured to hold the frame member (52) in the retained form. 6. Electrical ablation device (12), according to claim 5, characterized in that the retention structure comprises a sheath (40) defining a channel (15) configured to receive the structure member (52) within a distal portion thereof, wherein the frame member (52) is positioning a distal end of the distal portion of the sheath (40), wherein the frame member (52) is transitioned from retained form to memory form when installed from the distal end of the sheath (40). 7. Electrical ablation device (12) according to claim 1, characterized in that the frame member (52) is transitionable between a low temperature associated form and a high temperature associated form. 8. Electrical ablation device (12), according to claim 1, characterized in that the first frame (50) further comprises a proximal and distal coupler (54, 56) configured to couple the frame member (52) within the first structure (50), wherein the proximal and distal couplers (54, 56) are separated by a distance, and wherein the transition from the contracted state to the expanded state further comprises a reduction in the distance between the proximal coupler and the coupler. distal (54, 56). 9. Electrical ablation device (12), according to claim 8, characterized in that the decrease in the distance between the proximal and distal coupler (54, 56) articulates at least a portion of the frame member (52) to out of the axis. 10. Electrical ablation device (12), according to claim 1, characterized in that it further comprises: a second electrode (22) disposed along the elongated element (18) and extending along the axis, the second electrode (22) having a proximal end configured to couple to a power source (11) and a surface configured to couple to the tissue treatment region; a second expandable portion (20) having a proximal end and a distal end and extending along the axis, the second expandable portion (20) defining a second perimeter of the second electrode (22) having a second diameter associated with respect to the shaft, wherein the second expandable portion (20) comprises a second frame (50) comprising one or more second frame members (52); and the second selectively expandable structure (50) for transitioning the second expandable portion (20) from a contracted state to an expanded state, and the second selectively expandable structure (50) for transitioning the second expandable portion (20) of the expanded state to the contracted state, wherein, when the second structure (50) is expanded, the second diameter is expanded and the second expandable portion is transitioned from the contracted state to the expanded state, and wherein, when the second structure (50) is contracted, the second diameter is contracted and the second expandable portion (20) is transitioned from the expanded state to the contracted state. 11. Electrical ablation device (12), according to claim 10, characterized in that the first electrode (21) and the second electrode (22) are separated by a distance along the elongated element (18), and in that the distance between the first electrode (21) and the second electrode (22) is selectively adjustable. 12. Method of treating tissue electrosurgically, characterized in that it comprises the steps of: obtaining the electrical ablation device (12), as defined in claim 1; releasing the first electrode (21) to a tissue treatment region comprising a biological lumen; expanding the first electrode (21); placing the first electrode (21) in contact with a wall of the proximal lumen in the tissue to be treated; and treating the tissue by applying, with the first electrode (21), one or more sequences of electrical pulses to the tissue to be treated sufficient to induce cell death in the tissue by irreversible electroporation. 13. Method of treating tissue electrosurgically, according to claim 12, characterized in that rotating the helix in a first direction within the biological lumen to continuously treat the entire biological lumen.

Images